We have an ISA 2006 build 5.0.5712 operating as our web proxy. We have WPAD configured both in DNS and in DHCP to point to this ISA server. There are two sites (rentsentinel.com and epmsonline.com) which when we use the 'Automatically detect settings' option in IE8, it either gives red X'es in part of the homepage (rentsentinel), or doesn't show the page at all (epms). If we manually specify the proxy settings for this same server, it works fine. It would also appear that one can browse fine on random sites, but once we attempt to browse to once of these two sites that further browsing, even to sites which just worked fine, no longer works.
I'm looking for help on getting these sites working correctly with automatic detection. Thanks!
Edit: If I manually specify the http://wpad/wpad.dat file in the config field, no change in behavior. But if I use that same entry in Firefox, both websites render fine.