[horde] groupware webmail edition 5.1.1: Dynamic view and attachments

[steffo76 at gmx.de]

> is anybody else having problems attaching files in dynamic view
> after the latest update/ imp version 6.1.3 ?


This is getting weirder by the minute... On one server I simply cannot send attachments in dynamic view, I checked with several browser versions up to Firefox 22.0. I cleaned the browser cache, I deleted horde cache files. No dice. Meanwhile on another server with the exact same php and horde version I can send attachments using the same browsers.... 
Symptoms: In IMP dynamic view I add an attachment and IMP tells me that the attachment has been added. In debug mode the horde log says: 

1. Horde_Core_Ajax_Application->doAction() /var/www/htdocs/horde5/services/ajax.php:58
2. call_user_func() /usr/local/lib/php/Horde/Core/Ajax/Application.php:162
3. IMP_Ajax_Application_Handler_ComposeAttach->addAttachment()
4. IMP_Compose->addAttachmentFromUpload() /var/www/htdocs/horde5/imp/lib/Ajax/Application/Handler/ComposeAttach.php:58
5. IMP_Compose->_addAttachment() /var/www/htdocs/horde5/imp/lib/Compose.php:2871
6. Horde_Mime_Magic::analyzeFile() /var/www/htdocs/horde5/imp/lib/Compose.php:2907
7. finfo_open() /usr/local/lib/php/Horde/Mime/Magic.php:156
8. Horde_ErrorHandler::errorHandler()

No error message occurs after sending but the mail arrives without the attachment as simple text/plain.

Any ideas ?

Regards
Stephan