Is that really a big issue? Most other forums have similar sized windows.
It's not big - All the sideway scrolling just gets on my nerves. I just thought you could do it when you're working on the forum anyway, because it's a matter of a minute to fix it. Take the image, resize it, done. No need for another theme.
Look, I allready made most of the work:
Instead of 950 px it's now 814 px (in case it's too small now, I'll happyli redo it)
Replace the original logo.jpg with this one (keep a copy of the original, just in case) and all should be good. The forum may have the size hardcoded into it (in which case the image would stretch sidewasys to the same width), but I doupt that
(you may notice that I diddn't resize it, i just narrowed it. It makes no difference in looking at it but it solves the problems in sideways scrolling for the people here who have a small screen/resolution or prefer to not maximise the browser because they have a linux shell open in a putty window where stuff compiles. yes, the latter will not be the case too often ;P)