[canadave]

HOWTO FIND THE BUILD INFO:
In Confluence, the default theme, arrow down to System and right arrow. You will be presented with a 'System Info' page. Select that and you should have build e.g. Git:d538b07(Compiled on Feb 6 2011)
Also list where you got the build, self compiled, which unofficial one, xbmc official release, etc.

Just wanted to add that if you can't access your ATV2 to get this info, you can simply grab the debug log (see procrastinator's post above mine here), and look at the first line in the log. It provides the same info.

In fact, since you're getting the debug log and pasting it anyway as part of your bug report (right? Right?? ), you might as well just get it that way and not bother going into your ATV2 separately to get that info.