GroupWise system: GroupWise 8.0.1 HP 1
GroupWise client: Build 89145 (Windows)
Server OS: OES2 SP2
TimeZone: GMT +2 Harare/Pretoria (this time zone has NO daylight savings)

Calendar work schedule shifts to one hour earlier on 7 May 2010 and back on 29 September 2010

Manually changing the work schedule in Tools | Options | Calendar | Work Schedule tempoararily fixes the problem. After about 5 minutes the work schedule changes back to an hour earlier/later on the above dates.

Have checked server time zone: Africa | Johannesburg | Local Clock set to UTC

GroupWise MTA & POA time zones all set correctly

Any ideas??? Is this a bug ???