I had a similar problem with a "unsupported header" problem about two years ago. In fact, from what I recall, I never was able to resolve the issue. I ended up building a new ISA Server from scratch and it worked fine. I agree with the thought that it was the site causing the problem. However, after making a bunch of changes on a production server that didn't fix it, left me feeling a bit leery about its stability. Therefore, I started from scratch with a new one - and behold, the problem was resolved. Sorry I wasn't of much help. but good luck none the same. J -Paul From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Mayo, Bill Sent: Wednesday, February 13, 2008 4:43 PM To: isalist@xxxxxxxxxxxxx Subject: [isalist] Error 502 in browsed site I am running into a problem that appears to be well documented, but I am not having any success in getting it to work. I have a user going to a "critical" (sigh) site that is causing ISA 2006 EE to throw a 502 error to them, and in logging it shows: The HTTP message includes an unsupported header or an unsupported combination of headers. (12156) . I have found KBs regarding this error, the most pertinent seeming to be 935693. I have downloaded and installed the "ISA Server 2006 Supportability Update package", which indicates that is addresses this issue. I also have applied the registry changes that are indicated in 935693. Unfortunately, the error persists. I am wondering if a reboot or services restart is necessary after the registry change, but the article doesn't indicate one way or other (I will try that after hours). I understand that, at its core, this a problem with the site they are visiting. However, I have no realistic way to get this addressed on that end, and the client wants it fixed now. Is there anything that I am missing, or any pointers anyone can provide? ~~~~~~~~~~ Bill Mayo Network Administrator Pitt County MIS V:252-902-3831 F:252-830-6361 E:bemayo@xxxxxxxxxxxxxxxx