**NEWSFLASH** With a reply from Mark/Space's Technical support department involving a previous, similar case of theirs that involved iSync, I've got the solution!

I quote below from a post on their discussion board that was included in the email reply from Mark/Space. (Note: Just substitute "Entourage" where you see "iSync".).

**For the record, I only needed to perform Step 5 and it worked, so as the author says, try this first, do a HotSync and then see if it works before doing other steps.**

[i]"...it appears the root of the problem has to do with the application and conduits Verizon uses to sync with its mail server. I could sync fine and with almost no effort -- until I used the Wireless Sync application on the Palm that syncs with the Verizon email server. This phenomenon was totally replicable: HotSync/iSync, fine. Repeat, repeat, repeat. Wireless Sync with Verizon, fine on its own, but iSync wouldn't work from that point forward. If I did a hard reset on the phone (i.e., the handheld nuclear option), I could repeat that last sequence ad infinitum.

Specifically, the problem seemed to arise from Verizon's default "feature" of replicating EVERYTHING on the phone to their server. After much trial and error, the fix below works for me. [It may be possible to skip the hard reset, but now that everything's working, I'm afraid to do any more testing. My advice is to try just step 5 first. If that doesn't work, try steps 3 through 5. If that doesn't work, try the whole thing.]

1. Do a hard reset of the phone. This erases all the data and user apps on it.

2. Turn on Bluetooth, set the user name, and make sure it is "discoverable."

3. Go to the Wireless Sync application on the Treo, and select Settings > Sync Settings. Deselect all the options (I believe these are Intellisync conduits, although I'm not sure) except those for Inbox, Outbox, and Drafts.

4. Repeat step 3 above for the Settings > SyncXpress Settings menu.

5. While still in the Wireless Sync application, go to the Setup > Connection Settings menu. Click the Advanced button at the bottom and make sure "Enable other sync apps" is checked.

6. If you haven't done this already, set up the PDA as a favorite Bluetooth device on the Mac.

7. On the Treo, go back to Bluetooth preferences and set up the device. Go through the menus (ignoring their instructions to create a virtual serial port), and finish it off with a HotSync. This assumes that you've properly set up HotSync and iSync in the first place.)

8. After that HotSync is finished, go to the mail application and click on the refresh icon to initiate the sync with Verizon (this is set up on the web at http://www.wirelesssync.vzw.com).

9. After that sync is finished and you've downloaded your mail, repeat step 5 to make sure the "Enable other sync apps" checkbox is still checked.

10. Change a couple of records, and HotSync again.

P.S. For the author's original post and complete thread on the subject, go to Apple's Discussion board here: http://discussions.info.apple.com/we...hh.2@.68b071f8