Currently this button redirects you to another page, and going back to the original page doesn't keep the state of the controls on the page. For example, if you're on page 8 of the builds for a revision, you need to manually click the Next button to go to the page 8 to continue from where you left off. I think it's best for the Rebuild button to not redirect, and just show the result of the Rebuild request somewhere on the page.
dup of bug 627566? I would also hazard a guess that all the self-serve whiteboard items can be duped against Catlee's original statement that "Really, the goal here wasn’t to create a fully functional web interface, but rather to provide a functional programmatic interface."   https://bugzilla.mozilla.org/buglist.cgi?resolution=DUPLICATE;resolution=---;status_whiteboard_type=allwordssubstr;query_format=advanced;status_whiteboard=[self-serve];component=Release%20Engineering;component=Release%20Engineering%3A%20Custom%20Builds;component=Release%20Engineering%3A%20Future;product=mozilla.org  http://atlee.ca/blog/2011/02/17/self-serve-builds/ I'll leave this open, however, in case it's not a dup of bug 627566.
DUPE of bug 636027 or bug 627566. Patches welcome to fix up the UI, but I'm not going to be putting much time into it in the next month or so.