Exchange/OWA password IIS error 5

Many of our users only have acces to OWA to change their password. They were getting an IIS error 5 when trying to change it. I deleted the IISADMPWD Virtual Directory and recreated it on the server and this seemed to fix the problem for a while but now it has reappeared and that fix is not working. Anyone else having this problem? Running 2k3 sp1 w/ Exchange 2k3 sp2 and Mcafee Groupshield for Exchange. All patches are current.