You mean to change the 100% to $stylevar[outertablewidth]?
Tried it and can see no difference at all.
Is the footer on your forum wider than the other elements on the page? Here on Vbulletin.org the navbar and the footer are wide and everything in between is narrower, on mine the navbar is the same width as the the stuff in between.
--------------- Added [DATE]1212354268[/DATE] at [TIME]1212354268[/TIME] ---------------
Here's the difference (I think). To widen the navbar you must change class from "tborder" to "page" and change width from"100%" to "$stylevar[outertablewidth]"