The bleeding edge: one reason it is better to wait for awhile to upgrade your Mac OS to Leopard
Palm Treo synchronization is apparently broken under Mac OS X 10.5.x Leopard. I went to sync one of my two Treos (my work Treo) to my work MacBook Pro which is running Leopard. The Leopard version of iSync did not even see the Palm device.
I went to Apple's forums to see if I could find a fix. This is what I found there, "There are currently undefined issues regarding Palm synchronization under Mac OS X 10.5 and 10.5.1."
I went to Mark/Space's Web site. This company makes the Missing Sync products for synchronizing devices like Treos to to Mac OS X running computers. Here is what I saw there, "As we confirm issues, we will post summaries for each product. We recommend that The Missing Sync not be used with Leopard..."
I had been considering upgrading my own MacBook that I use for syncing my other (personal) Treo to Leopard. That plan is on hold and my work Treo is now a disconnected device. This is another reason to wait until Mac OS X 10.5 has been through several Rev's before upgrading. If you don't need it, if you don't gotta have Leopard now, if getting your work done is more important than being on the bleeding edge; I say, stick with Tiger!