Checked the registry, the entries for time zones (under "HKLM\Time Zones\") seem to indicate the DST stuff mandated by the Energy Policy Act has been applied to the WinCE 5.0 Platform Builder that Pioneer's using, so much for hoping it was stale TZ rules and auto DST screwing up the hour.

I have F90BT ver2.0 and also my clock didn't update this past weekend, I haven't got into the AVIC system yet, my first thought was Microsoft had the TZ screwed up like they have been doing in the registry for the past 10 years...several or more TZs always had something wrong with them. Here is the dump for US Central Time zone in the registry for XP which is correct. The satellites outputting zulu.
68 01 00 00 00 00 00 00 c4 ff ff ff 00 00 0b 00 00 00 01 00 02 00 00 00 00 00 00 00 00 00 03 00 00 00 02 00 02 00 00 00 00 00 00 00
Rather difficult to read, but if you know the format its not too bad. -360 minutes from zulu, DST End time is 11th month, 1st week, Sunday, 2AM; DST Start time is 3rd month, 2nd week, Sunday, 2AM
I would like to go in and check this on Ver2...can someone tell me what I need to get into the AVIC?