Strange occurrence last night. Android 1.6 on my G1 stopped advancing the clock. Time on the windowshade continued to show 9:35 PM all through the early hours of this morning. Phone had been rebooted yesterday prior to the problem. It may be related to clearing the cache and data on several apps to free internal memory. Calendar had swelled to 1.5 MB of data so I cleared it as well. After rebooting the G1 this morning it reloaded calendar data (only about 1/2 MB this time) and clock is working normally).