No image processing

i upgraded to 5.x-3.0 and bg stopped working. i use the bg tag on pages, stories and blog entries to embed pictures. i have looked at the other issues in the list and they don't seem to describe the problem i am seeing.

here is what happens:
- a blank area with the right background colour shows up where the thumbnails should be
- no image thumbnails are visible
- hovering over the bg album area with the cursor reveals that there are no (hidden) hyperlinks
- the tag is being processed, because when i change the background colour on the tag, the background color changes to the new color set in the tag

i have eliminated all trivial, configuration related explanations - becuase everything works fine if i just go back to bg 2.17. i first thought that this was a permissions issue, but have been able to eliminate that. going back to bg v2.17 alway fixes the problem and everything works fine.

installed and reinstalled brilliant gallery 3.0 on a test site, cleaned out the file cache in the tmp directory where bg stores its processed images - nothing helps. change to bg 2.17 and no problems whatsoever on any of the sites.

i am running my installations on a suse linux 10.1 box with apache. i am using a lot of contributed modules and i wonder if one of them has a conflict with bg 3.0?