@mark: Thanks for the information.
Well i have a Debian testing installation with:
( phpinfo() )
PHP Version 4.3.10-16
GD Support enabled
GD Version 2.0 or higher
FreeType Support enabled
FreeType Linkage with freetype
T1Lib Support enabled
GIF Read Support enabled
GIF Create Support enabled
JPG Support enabled
PNG Support enabled
WBMP Support enabled
SO i have all the needed Files. But the Problem still exits. I have no idea… And yes: I restartet the apache server
Maybe it would be a good idea make wordpress supporting “convert” from ImageMagick