User maintains a very detailed calendar of events for the entire org. Recently, newest events were off by 3 hours. enabling the show timezone settings showed that her default TZ was set to PST. I confirmed this by zmprov ga on her account. she was using FF1.5 on windows xp, i upped her to FF2 but no change.
If i login with her account on FF2 OS X, EST is restored on both new events and in zmprov ga.
I've checked her windows timezone and it appears to be correct.