Palm will not Hot Sync

My client has a Palm m515. The cradle has a serial/com cable. I had to remove the Palm software and reinstall it under her profile. This is the latest version of the Palm Desktop. She is using Windows XP Pro. I have tried both com ports. When I press the Hot Sync button, nothing happens. When I use the HotSync on the Palm, it tries to connect to the PC but cannot. The Hot Sync settings are set to Serial. This Palm/Cradle works on another computer. In the Device Manager, both comp ports appear to be okay.