Microsoft has a page for this issue called Windows Mobile Updates for Daylight Savings Time.
These instructions are for people who sync their Ipaq to their PC - like me. If you sync it over wireless, or over the phone or something, go the web-page for instructions that address your configuration.
- First make sure to update your PC by installing the 2007 time zone update for Microsoft Windows operating systems. This will update the clock on your PC.
- If you use Microsoft Outlook to synchronize your calendar, download and run the Outlook Time Zone Update Tool. If you do not use Microsoft Outlook, proceed to step 3.
- Check to make sure you have the latest version of ActiveSync, which is ActiveSync 4.5.
- Next, connect your Windows Mobile device to your PC, then download and run the Daylight Saving Time 2007 Update Tool for Windows Mobile.
All the usual legal disclaimers apply: proceed at your own risk; no guarantees or warranty intended or implied; not liable for damages due to use, misuse or anything else; your mileage may vary; beware of the dog, etc., etc.