Filesystem error with watermark?

Hi,
I transfer this domain to a new server.
Everything works fine. file upload, changing and deleting, no problems at all.
but when I would add a watermark to a image, the Gallery says 'done' but nothings happened.

I think it is a problem with the file system (right and ownerships) but I don't know how to solve this. see the attachement for details.

thanks in advance.
Michael

The following information is required to get an answer:
Get this information from the PHP diagnostic (in the configuration wizard).
Gallery URL (optional but very useful):www.motorfoto.nl/g1
Gallery version:1.5.9
Apache version:2.2.10
PHP version (don't just say PHP 4, please):4.4.9
Graphics Toolkit:ImageMagic NETPMB
Operating system: Linux
Web browser/version (if applicable): 7.06