I also have this problem. To troubleshoot, I have disabled 1) internet time update feature in control panel 2) had all 3 computer check adjust daylight savings time, and later 3) had 3 computers disable adjust daylight savings time. Problem still pops up, but it is not a consistent error.

Also went through above exercise with iCal vs vCal feature without success.

All three outlook pst files show some corruption every few days.

Any ideas? Thanks in advance.