Hello samanthaob
The VPN may have some ports or network protocals blocked that are used by PWA. To verify this, have the user access PWA from behind the password. If it works, then the VPN or a proxy server is limiting some of the portals and/or network
protcals. Some VPNs use addtional network layer protocals such as ICMP, IGMP, IGRP, IPX, etc when accessing remote sites.
You can also test by setting up AAM (Alternate Addressing Methods) and just come into PWA using HTTPS.
Cheers!
Michael Wharton, MBA, PMP, MCT
Sincerely, Michael Wharton, MBA, PMP, MCT, MCSD, MCSE+I, MCDBA www.WhartonComputer.com