diff --git a/addons/document/document.py b/addons/document/document.py
index 3ae783f49e7..27dde3250e2 100644
--- a/addons/document/document.py
+++ b/addons/document/document.py
@@ -154,6 +154,7 @@ class document_file(osv.osv):
         parent_id = vals.get('parent_id', False)
         res_model = vals.get('res_model', False)
         res_id = vals.get('res_id', 0)
+
         if op == 'write':
             for file in self.browse(cr, uid, ids): # FIXME fields_only
                 if not name:
@@ -164,11 +165,11 @@ class document_file(osv.osv):
                     res_model = file.res_model and file.res_model or False
                 if not res_id:
                     res_id = file.res_id and file.res_id or 0
-                res = self.search(cr, uid, [('id', '<>', file.id), ('name', '=', name), ('parent_id', '=', parent_id), ('res_model', '=', res_model), ('res_id', '=', res_id)])
+                res = self.search(cr, uid, [('id', '<>', file.id), ('name', '=', name), ('parent_id', '=', parent_id), ('res_model', '=', res_model), ('res_model', '!=', ''), ('res_id', '=', res_id)])
                 if len(res):
                     return False
         if op == 'create':
-            res = self.search(cr, uid, [('name', '=', name), ('parent_id', '=', parent_id), ('res_id', '=', res_id), ('res_model', '=', res_model)])
+            res = self.search(cr, uid, [('name', '=', name), ('parent_id', '=', parent_id), ('res_id', '=', res_id), ('res_model', '=', res_model), ('res_model', '!=', '')])
             if len(res):
                 return False
         return True
@@ -219,7 +220,11 @@ class document_file(osv.osv):
         res = self.search(cr, uid, [('id', 'in', ids)])
         if not len(res):
             return False
-        if not self._check_duplication(cr, uid, vals, ids, 'write'):
+
+        # when a user write a mail, there are no model
+        # don't check the duplication for the mails
+        res_mail = self.search(cr, uid, [('id', 'in', ids), ('res_model', '=', '')])
+        if res!=res_mail and not self._check_duplication(cr, uid, vals, ids, 'write'):
             raise osv.except_osv(_('ValidateError'), _('File name must be unique!'))
 
         # if nodes call this write(), they must skip the code below
diff --git a/addons/mail/mail_thread.py b/addons/mail/mail_thread.py
index da4143df909..4e8d036d68a 100644
--- a/addons/mail/mail_thread.py
+++ b/addons/mail/mail_thread.py
@@ -697,7 +697,7 @@ class mail_thread(osv.AbstractModel):
     def message_post_api(self, cr, uid, thread_id, body='', subject=False, type='notification',
                         subtype=None, parent_id=False, attachments=None, context=None, **kwargs):
         # if the user write on his wall
-        if self._name=='res.partner' and (not thread_id or not thread_id[0]):
+        if self._name=='res.partner' and not thread_id:
             user = self.pool.get('res.users').browse(cr, uid, uid, context=context)
             thread_id = user.partner_id.id
 
diff --git a/addons/mail/static/src/css/mail.css b/addons/mail/static/src/css/mail.css
index 9133078d433..c2abc6a5882 100644
--- a/addons/mail/static/src/css/mail.css
+++ b/addons/mail/static/src/css/mail.css
@@ -245,6 +245,7 @@
 .openerp .oe_mail_msg_email {
     padding: 8px;
     background: white;
+    position: relative;
 }
 
 .openerp .oe_mail_msg_notification:after, 
diff --git a/addons/mail/static/src/js/mail.js b/addons/mail/static/src/js/mail.js
index 599241e598f..8fab771fcc0 100644
--- a/addons/mail/static/src/js/mail.js
+++ b/addons/mail/static/src/js/mail.js
@@ -104,12 +104,13 @@ openerp.mail = function(session) {
             this.res_id =       options.parameters.res_id;
             this.is_private =   options.parameters.is_private;
             this.partner_ids =  options.parameters.partner_ids;
-            this.show_header_compose =  options.parameters.options.thread.show_header_compose;
-            this.display_on_flat =  options.parameters.options.thread.display_on_flat;
+            this.options={thread:{}};
+            this.options.thread.show_header_compose =  options.parameters.options.thread.show_header_compose;
+            this.options.thread.display_on_flat =  options.parameters.options.thread.display_on_flat;
 
             this.attachment_ids = [];
-            this.show_attachment_delete = true;
-            this.show_attachment_link = true;
+            this.options.thread.show_attachment_delete = true;
+            this.options.thread.show_attachment_link = true;
 
             this.parent_thread= parent.messages!= undefined ? parent : false;
 
@@ -147,12 +148,17 @@ openerp.mail = function(session) {
             var $target = $(event.target);
             if ($target.val() !== '') {
 
+                // if the files exits for this answer, delete the file before upload
+                var attachments=[];
                 for(var i in this.attachment_ids){
                     if(this.attachment_ids[i].url == $target.val()){
                         var ds_attachment = new session.web.DataSetSearch(this, 'ir.attachment');
-                        ds_attachment.unlink(this.attachment_ids.id);
+                        ds_attachment.unlink([this.attachment_ids.id]);
+                    } else {
+                        attachments.push(this.attachment_ids[i]);
                     }
                 }
+                this.attachment_ids = attachments;
 
                 // submit file
                 session.web.blockUI();
@@ -186,7 +192,7 @@ openerp.mail = function(session) {
                 this.display_attachments();
 
                 var ds_attachment = new session.web.DataSetSearch(this, 'ir.attachment');
-                ds_attachment.unlink(attachment_id);
+                ds_attachment.unlink([attachment_id]);
             }
         },
 
@@ -231,7 +237,7 @@ openerp.mail = function(session) {
             this.$('input[data-id]').remove();
             this.attachment_ids=[];
             this.display_attachments();
-            if(!this.show_header_compose || !this.display_on_flat){
+            if(!this.options.thread.show_header_compose || !this.options.thread.display_on_flat){
                 this.$el.hide();
             }
         },
@@ -455,10 +461,10 @@ openerp.mail = function(session) {
          * in the function. */
         bind_events: function() {
             var self = this;
+
             // event: click on 'Attachment(s)' in msg
-            this.$el.on('click', 'a.oe_mail_msg_view_attachments', function (event) {
-                var act_dom = $(this).parent().parent().parent().find('.oe_mail_msg_attachments');
-                act_dom.toggle();
+            this.$('a.oe_mail_msg_view_attachments:first').on('click', function (event) {
+                self.$('.oe_mail_msg_attachments:first').toggle();
             });
             // event: click on icone 'Read' in header
             this.$el.on('click', 'a.oe_read', this.on_message_read_unread);
diff --git a/addons/mail/static/src/xml/mail.xml b/addons/mail/static/src/xml/mail.xml
index db6935d7af8..cd14632ec6c 100644
--- a/addons/mail/static/src/xml/mail.xml
+++ b/addons/mail/static/src/xml/mail.xml
@@ -55,14 +55,14 @@
         Template used to display attachments in a mail.message
         -->
     <t t-name="mail.thread.message.attachments">
-        <ul t-attf-class="oe_mail_msg_attachments #{widget.attachment_ids[0]?'':'oe_hidden'}">
+        <ul t-attf-class="oe_mail_msg_attachments #{widget.attachment_ids[0] and widget.options.thread.show_attachment_link?'':'oe_hidden'}">
             <t t-foreach="widget.attachment_ids" t-as="attachment">
                 <li>
-                    <a t-if="widget.show_attachment_link" t-att-href="attachment.url"><t t-raw="attachment.name || attachment.filename"/></a>
-                    <span t-if="!widget.show_attachment_link"><t t-raw="attachment.name || attachment.filename"/></span>
-                    <t t-if="widget.show_attachment_delete">
+                    <a t-att-href="attachment.url"><t t-raw="attachment.name || attachment.filename"/></a>
+                    <t t-if="widget.options.thread.show_attachment_delete">
                         <a class="oe_right oe_mail_attachment_delete" title="Delete this attachmentt" t-attf-data-id="{attachment.id}">x</a>
                     </t>
+
                 </li>
             </t>
         </ul>
@@ -214,7 +214,6 @@
                     <ul class="oe_mail_msg_footer">
                         <li t-if="widget.author_id"><a t-attf-href="#model=res.partner&amp;id=#{widget.author_id[0]}"><t t-raw="widget.author_id[1]"/></a></li>
                         <li><span t-att-title="widget.date"><t t-raw="widget.timerelative"/></span></li>
-                        
                         <li t-if="widget.attachment_ids.length > 0">
                             <a class="oe_mail_msg_view_attachments">
                                 <t t-if="widget.attachment_ids.length == 1">1 Attachment</t>