I bet I know what your issue is. On the last step of install the incorrect server path to your vb forum was entered. you can either rerun install or even easier just ftp to your site and edit the config-int.php file and on the $vbpath line place the proper server path to your vbulletin forum and you will be fine. If there is anything else I can do to assist let me know.
I olso have this Issus when I have install this gallery to my vb 3.6.8
when I go to my gallery folder I only se white page insted off the index page but where can I finde this page
config-int.php file and on the $vbpath
If you need assistance with Photopost vbgallery as that is not Photopost Pro then please post a support request on that product in the proper forum thanks. There is no $vbpath variable etc and the thread your noting does not pertain to that product.