Exchange2010 not updating OAB/Outlook clients not downloading updated OAB

I have been trying to figure this problem out for a month.   We have Exchange 2010 running on Server 08 (SP2).    For over a month, any change made (IE:  New User, Removed User,  Name Change, etc) will not show up on the client side address book (Outlook 2007 or 2010).

There are A LOT or other forum topics like this and I've probably read them all.  None of them solve this issue for me, but they do help me find workarounds, which I hope can useful in finding a fix.

What I've learned:
- OWA is not affected at all.  All changes are instantly reflected in OWA.
- Disabling Cached mode on client manually fixes the problem (but I dont want to diable cache mode on 100+ clients)
- Deleteing the .oab files in the user app data folder fixes the problem, but again,  this is not a real solution.

What I've tried:
- The obvious,  updating the  default OAB.
- Restarting the server 100 times,
- Restarting the Microsoft File Distribution Service,
- and gently caressing the server with love.

Any ideas are greatly appreciated!