Ok, well, I never got around to testing whether the firefox maintenance service was the issue, because now it's broken again and the only thing I've done is installed some windows updates. I guess it's just something inherent in Windows 8 and I'll have to wait for MS to fix it. I did get to enjoy Pin Steam for a few minutes yesterday. Oh well.
I feel your pain. I haven't given up on 8, but I have given up on trying to fix/workaround these irritating bugs that are all Metro related.