vBulletin is working on that News link error, but I think it's a Firefox 4 bug because if you backtrace the code, the browser just seems to forget the value of SECURITYTOKEN, and I haven't had the issue in Chrome or IE9...
As for the Mobile Style, I know there were a lot of problems in the way vBulletin had designed it with respect to the style system, and fixing many of these issues so that addons can use it properly are one of the goals for their 4.1.5 release.
If there were other issues between VaultWiki and vBulletin 4, did you report them? I'm sure I would have fixed them if I saw them and they were something that was fixable from the VaultWiki side of the equation.
Anyway, marking this as fixed since the PM issue is solved.