Recently came across this problem on a Server 2008 box running Exchange 2007. Having downloaded the PFDAVAdmin utility and trying to connect to all mailboxes, it gives the below error when you try to expand any of them. Fortunately it’s a nice and easy fix!
Could not expand https://servername/exadmin/admin/domain/mbx/emailaddress/non_ipm_subtree/: Name cannot begin with the ‘0’ character, hexadecimal value 0x30. Line 1, position 417.
Run the PFDAVAdmin utility from a workstation, can download from HERE
Download Microsoft .NET Framework 1.1 HERE
DO NOT install this on the Exchange 2007 server as it will most likely reset the current .NET 2.0 settings and break Exchange 2007.