Is Google Browser Sync Plugin a troublemaker?

I just installed Google Browser Sync a few days ago, to manage my Firefox profiles across the computers, one in Gentoo, one in Windows XP(VMWare), one in Mac. Today, after the upgrade the world, the firefox failed to launch with this error message:

No running windows found
firefox-bin exited with non-zero status (1)

Have I broken something in the upgrade? I double checked the emerge log via genlop, and found nothing relavent. Then I check the strace output:

bookstack@tiger ~/.mozilla/firefox $ strace -e stat64 firefox
... ...
stat64("/home/bookstack/.firefox/*/compreg.dat", 0xbfefb368) = -1 ENOENT (No such file or directory)
stat64("/home/bookstack/.firefox/*/chrome.rdf", 0xbfefb368) = -1 ENOENT (No such file or directory)

It is quite strange that the Firefox would check HOME / . firefox, itissupposedtocheckHOME/.mozilla/firefox instead. There must be something wrong with the current profile. Here we are, the $HOME/.mozilla/firefox/profiles.ini is truncated to zero bytes! Once this is fixed, Firefox works again.

I don’t want to FUD Google Browser Sync, but it is the only relavent change about Firefox. If you have met the same problem, could you drop a comment here? I might need to dig into the source code before jumping to a conclusion.