It just happened again today and here are the details. The data on my desktop calendar disappeared again, either shortly after, (or right after,) resetting my PC. But just before I reset the PC, I was doing "online banking" when the website became uncooperative and eventually "froze up." I was unable to get out of this mess without doing the reset. Shortly after rebooting, I noticed the data missing from the calendar. BTW, I'm quite certain that it's not "the reset," itself, that is causing the problem. I reset the computer quite often without this problem occurring.

Needless to say, if I had known the calendar was about to do the "data disappearing act," I would have paid closer attention to everything going on before it happened. Fortunately though, I noticed the "missing data" BEFORE doing a "hotsync" and was able to restore the data from my Treo. As I said in my first post, this had never happened until I synchronized my prior PDA phone, (a Samsung i500,) with another computer. This problem seems to occur once every month or so. Does this added information help? Any ideas yet on how to fix this? Thanks.