[imp] Problems with attachments in current imp

[Martin Tessun]

Hi all,

as I believe it just works usually and this is only my problem, I just  
wanted to ask if someone has an idea, what can cause the following:

1. Create a new mail, add attachment (e.g. PDF file) send this mail  
==> attachment is too small and corrupted
2. Forward a mail with an attachment (e.g. PDF file) ==> attachment  
gets smaller than from the original mail and is corrupted.

I am using the following versions:
PHP 5.3.17 (cli)
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies
     with Suhosin v0.9.33, Copyright (c) 2007-2012, by SektionEins GmbH

Horde / IMP:
Horde     5.0.5
IMP   H5 (6.0.5)

PHP extensions:

     Ctype Support: Yes
     DOM XML Support: Yes
     MIME Magic Support (fileinfo): Yes
     MIME Magic Support (fileinfo) - Configuration: Yes
     FTP Support: Yes
     GD Support: Yes
     Gettext Support: Yes
     GeoIP Support (PECL extension): Yes
     Hash Support: Yes
     Iconv Support: Yes
     GNU Iconv Support: Yes
     Internationalization Support: Yes
     Imagick (PECL extension): Yes
     JSON Support: Yes
     LDAP Support: Yes
     LZF Compression Support (PECL extension): Yes
     Mbstring Support: Yes
     memcached Support (memcache) (PECL extension): Yes
     MySQL Support: Yes
     OpenSSL Support: Yes
     PAM Support (PECL extension): Yes
     PDO: Yes
     PostgreSQL Support: Yes
     Session Support: Yes
     SimpleXML support: Yes
     Tidy support: Yes
     XML Parser support: Yes
     Zlib Support: Yes

I already tried to disable fileinfo, with no success.
So anyone an idea, what is going wrong there?

If you need more information, please ask.

Thanks and Regards,
Martin