I've had BES and ZCB working for a couple weeks. I went in to provision another user yesterday and my Global Address List was almost completely empty. There should be (and used to be) almost 3000 users in it.
I went back to the Zimbra server and ran this command...
Which returned 2816, the number of names that should be in the GAL.
zmprov syg domain.com | grep "name id" | wc -l
Rebooted the BES/ZCB server...still nothing. Tried running the "Update Global Address List" from Outlook....and still nothing. Just one account in the BES GAL.