OSX 10.8 users of plus.google.com get "browser is not supported" (TBB 2.3.25-11 and 3.0alpha2)
Users with OS X 10.8 and TBB 2.3.25-11/3.0alpha2 (may also affect users with other OS X and/or TBB versions) get a message saying their browser is out of date when they visit plus.google.com.