Hello Sam,
This is Kevin from Palm. What application are you in when the resets occur? Generally, third-party applications are the source of resets. One way to determine what software may have caused a reset is to dial a special code which accesses the error log and which can identify the application causing the problem. You can find out how to do this in the Palm Knowledge Library article
"Find out if your Treo 650 or 600 reset itself (and the error code it recorded)".
You can also troubleshoot the problem and determine whether it is indeed a software problem. You'll need to do a hard reset, then *before* you hotsync again, re-name the Backup folder on your computer to "backupold". This will prevent your third-party applications from re-installing. Then you perform a hotsync, and see if the problem persists. If all seems well, then re-install your third-party applications one at a time from the re-named backupold folder. After you install one (with hotsync) use the Treo and see if it's still OK. If so, then re-install the next app...and so on. You can also find a step-by-step description of this process in the article
"Diagnosing problems caused by third party applications".
Sincerely
Kevin