This is from MacFixIt yesterday;
Palm confirms that Desktop Software 4.1 problem We previously reportedproblems with the installation of Palm's Desktop Software 4.1 under Mac OS X 10.2.8. Now MacFixIt reader Kate has confirmed with Palm technical support that the software will have problems Mac OS X 10.3 (Panther) as well:
"The Palm Desktop software is not currently compatible with the Mac OS 10.3. Palm Engineers are aware of this issue and are working on an upgrade. Currently, there is no fix available for the issue, I suggest you to keep checking the following Palm web site for updates: http://www.palmone.com/us/support/downloads/"
UPDATE: Joshua Ochs reports a workaround for problems using HotSync, which are apparently the root of the incompatibility statement from Palm.
""It appears that the Palm Desktop installer is choking on installing the HotSync libraries. It further appears these can be copied over from Jaguar (or, if you're upgrading, then they'll already be in place). The critical files are in /Library/Application Support/Palm Hotsync and /Library/CFMSupport/Hotsync Libraries.
"I have not verified that a Hotsync will actually take place (as I have not finished upgrading), but this does resolve the problem of Hotsync Manager and others not launching with shared library errors.
Some readers have reported no problems running HotSync from a fresh installation of the Palm Desktop 4.1 software.