Update Rollup 5 for Exchange Server 2007 (KB941421) has been released

I still can't get my Entourage users connected.  The error is still ‘HTTP/1.1 503 Service Unavailable’, and this is after uninstalling UR5.  I went ahead and built a new CAS machine and installed only UR4.  Strangest thing...  It has the problem too...  I think the problem now exists at the mailbox store.  Originally the /Exchange URL didn’t respond at all, but now I get the Forms Based Authentication page and only get the Service Unavailable message after entering my credentials.  I rebuilt the OWA virtual directories on the original CAS machine after uninstalling the update and it’s healthier now as well, but still seems to be related to the mailbox store.  I’m currently trying to uninstall SU5 from my CCR mailbox store, but it has been over an hour and it’s just sitting at Add/Remove programs with a dialogue box that says Microsoft Exchange Server.  It didn’t bring up the SU5 setup to do the uninstall like the CAS machine did.  A bit strange.