It is throwing an error for every single relative url reference on the page. I personally used full (absolute) urls in all my custom work, so the errors are coming from relative urls from vBulletin's own templates that are being called like "headinclude", "navbar", etc.
For example these are the errors produced by just my CMS page that resides in the root:
Code:
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/cms, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/cms, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/cms, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/buttons, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/cms, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/site_icons, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/cms, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/misc, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/misc, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:47 2012] [error] File does not exist: /home/cruisin/public_html/images/customlogos, referer: http://www.cruisin.me/
[Thu Aug 02 14:25:46 2012] [error] File does not exist: /home/cruisin/public_html/clientscript, referer: http://www.cruisin.me/
The odd thing is the pages still seem to render correctly.