My best guess is that you've triggered a Bluetooth implementation bug in your specific configuration, and that it will eventually fall to Apple to correct the problem. It appears from Mark/Space technical notes that this is an isolated issue, but one that they should probably be aware of at some level.
You can try to reset your Bluetooth configuration by launching the Terminal application and executing these instructions:
sudo killall blued
sudo rm -f /private/var/root/Library/Preferences/blued.plist
The either immediately log out and log back in, or simply reboot.
Again pair your Palm device and synchronize and add back your mouse and keyboard, one at a time, to see if either interferes with Bluetooth communication.
You'll likely have to deal with Mark/Space on this issue, though you could call Apple at (800) APL CARE and attempt to escalate it until you can reach someone specifically familiar with Bluetooth issues. In order to submit an actual RADAR bug report, you must yourself be a developer and be able to reproduce and document the issue. That may be difficult for the technical staff at Mark/Space to do if they cannot reproduce the issue in house. The underlying issue may already have been reported to Apple, though I have no way of knowing about other RADAR submissions.
If you cannot resolve the issue by dealing with Mark/Space and Apple, send a message detailing what you've attempted to do to date, and I will be sure that it gets some attention. This can be a slow, tedious process, particularly if a bug is identified, as it takes engineering personnel a good deal of time to thoroughly investigate and correct an issue.
