We have a Win 2008 / 2003 AD network with a main office and five regional offices; each regional office is on a different subnet. All of our users are running Win XP. Everything was fine until a few weeks ago. Now when users in the regional offices try to access files in the home office (different subnets) via a UNC path the files do not open, no error just no response. The same UNC path works in the user and the file are on the same subnet. The only thing that has changes is that we rolled out SEP version 11 MP3, previously we were running SAV 10. We also released the latest round of MW security updates via WSUS. Any suggestion?