Don't have much to go on here. When did it start happening? From day one? After you installed some software or did an upgrade? Did you make any configuration changes? Throw us a bone.
There is some interesting suggestions in this thread that may help you. I sounds like you may have some 3rd party software running on the palm. If that is the case I would remove the software one application at a time to see if this resolves the problem.
Also, did you install a new desktop? I ask becasue it is not clear if this is a new install or you are upgrading to a TX from an older model. If you have older software on the PC and you use a new handheld (same userid), I think the sync process will result in older software to be restored to the new handheld and this may cause problems also. the older software my not be compatable with the newer OS.