[TheLastSuperman]

Hmm looks like their logo is on the left with the login on right... You could see what div class is doing that background bar, then simply try to replace the background url in the css with your new one. and make the current logo a clickable (blank transparent .png image file) image that way you can still click the logo in a sense and go to forumhome.

Probably a few different ways you could go about this but I'd simply figure out what area does that background image, replace it with the banner and replace the logo with the transparent image. I can't recall but PureVB may use a plguin with his styles, some vendors do and some don't but what I'm hinting at is, if yuou can't find it in the css templates or an external css file they've included it could be in a custom stylevar setting.