I have to thanks Lauren for bringing this to my attention. She had found my posting on how to update Exchange so that this did not happen, but she could not get the SBS / Exchange Server updated. Her research said that using Firefox would fix the problem , but to me this was just a huge sledgehammer...
I've talked about this before, but thought it was worth pointing people to this Installing a Self-Signed Certificate as a Trusted Root CA in Windows Vista [Today's post comes to us courtesy of Wayne McIntyre] In order for RPC over Http to work you must have a Trusted CA Root Certificate installed...