[TheLastSuperman]

I would simply uninstall VBSEO and utilize vB4's mode rewrite friendly url's. Did you know vBSEO left an exploit in the official product for well over a year through countless versions a known exploit was released in your vBSEO versions... ohh tis true and I recently uninstalled and even that had some issues glad I know my way around a vBulletin site well enough to fix it lol.

Example: http://www.vbseo.com/f5/vbseo-securi...tml#post325845

^ Post date is 01-23-2012 11:37 PM now read the post further...

Said activity has occurred sometime in the last month *starting December 1st, 2011* (as stated above)

The "sometime in the last month" but "starting December 1st, 2011" is what clues you into that. My site was hacked into as well including some of my clients long long ago so long story short I do not advise you keep it installed in fact I advise you remove it promptly and yes your SEO will take a hit, you can use "Mod Rewrite Friendly URLs" via your options in vBulletin though with an .htaccess file and redirect old threads then re-submit to google to be re-indexed and while that is a slight pain it's well worth it in my opinion.

http://www.vbseo.com/blogs/mert-goek...all-vbseo-238/
http://www.vbseo.com/f55/how-complet...l-vbseo-20737/

Just my 2 cents .