Palm z22 USB won't stay connected

When I plug in the USB cord to sync the palm to my computer, it won't stay connected. It recognizes the device, pops up a screen saying a new device was located, then the palm disconnects. then it reconnects. the whole thing is accompanied by the continuous beeping sound indicating that a new USB device has been connected...disconnected...connected... and so on. Tried resetting with no success. I'm running windows vista, but had the same problem when i tried syncing on windows xp. any suggestions?