Hello
I can not say exactly what the issue is since all I see is a white page. Now off hand coupe things here. If you have phpmyadmin check your photopost settings table in the database and make sure the urls entered correctly in the first 20 settings of that table
Now I would assume here the first issue I see on your site is that your forum server path is incorrect. Try turning off your vb3 integration switches from on to off in config-int.php and see if Photopost loads. If it does then check the $vbpath variable and make sure it is the correct server path to your vbulletin forum and turn the switches for vb3 integration back on and see if the page loads now. I see just a white page with nothing now.