How many images (especially smilies & post icons) do you have? If you have a lot and are on a machine with not a whole of memory you may running out of memory.
The images are one of the last parts of the installation though should you should be able to skip around it. To be on the safe side re-run vbagallery_install.php and choose the various options (upgrade, re-install templates, re-install phrases, etc.) but don't do the graphics option. You then should see the Gallery settings in your ACP. If yes, then you'll need to manually update your graphic paths.