The data for the IceTV Guide is sent out in UTC format and then displayed in MCE according the time settings of the PC.
There was a patch that was released for Windows XP Media Center Edition 2005 that fixed the timezone change for the Commonwealth Games this year.
One thing that will affect this is whether or not the hotfix for daylight savings has been installed on the MCE system. Unfortunately with or without this patch the timezone and time can appear correct even if they aren't.
To fix this you will need to change from the correct timezone to some other timezone, apply these settings and then go back to the correct timezone. You can tell if the correct timezone is set if on the "Date & Time" tab of the "Date & Time" control panel the timezone is listed as "AUS Eastern Daylight Time" instead of the incorrect "AUS Eastern Standard Time" (This will be for the Canberra, Melbourne and Sydney timezone).
You can check to ensure that it the hotfix installed from the "Add or Remove Programs" control panel. Once the control panel is open you will need to tick the box marked "Show Updates", this will list all Windows Hotfixes and patches as well. The hotfix for daylight savings changes is "Hotfix for Windows XP (KB912475)".
If it's not installed then it can either be gotten from Windows Update or directly from Australian daylight saving time 2006 update for environments that do not use Exchange Server.