shouldberiding

My X5 is about 3 years old and has worked great until recently. 4 times in the last 2 weeks I totally lost only the appointment data. No warning and all batteries are good. Dell said they never heard of this (appt. data loss only) and had me do a hard reset, which I haven't done before. I'm not sure or very optomistic that that fixed the problem. I didn't expect to lose all I lost with the hard reset, but will eventually get it back to the way it was. The most important items synced back anyway. If the hard reset doesn't fix the problem, are these usually worth fixing or not? The X51v looks really nice, but seems there are a lot of problems with them? I'd hope the latest ones coming out should have the big bugs worked out? I'd appreciate any advice. Thank you!