Enough people have had success with this trick published in a recent Macworld Weekly newsletter that I thought I might repost it here.
Q. I use iSync and iCal to sync my Palm Zire 71 with my 12" PowerBook. Since I upgraded to Panther I cannot reinstall Palm Desktop. Are there any workarounds to make my Palm syncable again?
-- Chris Andress
A.You're dealing with a couple of different issues here. The first is that the installer may not work properly if you've expanded the Palm Desktop 4.1 archive with StuffIt Expander 8.0. You'll likely have more success if you expand the archive with StuffIt Expander 8.0.2.
The other issue is that even after you've installed Palm Desktop, iSync may not see the Zire. I had a similar problem under Mac OS X 10.3.1 with my Tungsten T2, but was able to fix it by installing Palm Desktop, then reinstalling iSync 1.3, and finally installing iSync Palm Conduit 1.2.
Before I'm deluged with email on the subject, allow me to acknowledge that this is a slippery issue. Many people have had no problem syncing their Palm devices after upgrading to Panther. Others have gone the reinstallation route and have met with failure. If you're interested in reading more on the subject (as well as perusing a few other methods for making Palm Desktop work under Panther), Rob Griffiths' Mac OS X Hints site has an interesting thread on the subject.