Hi *.* We have ISA 2004 server that is working fine so far. After installing SP2 things continue to work fine except one little problem: When we try to access some web sites such as www.delta.com we're getting the following message: =========================================================================== Technical Information (for support personnel) Error Code: 502 Proxy Error. The HTTP request includes a non-supported header. Contact your ISA Server administrator. (12156) IP Address: 205.174.16.50 Date: 3/5/2006 12:53:52 AM Server: isaServerName.DomainName.com Source: proxy =========================================================================== I am looking for a solution for this problem other than un-installing SP2 because it really fixed more serious problems than this problem. Also other than chaining to another ISA server with SP1. The Result of my research indicated that this a bug with SP2, and Microsoft is working on a hotfix for, which will be out some time soon. just to let you all know I have contact MS Support as well, and they told me the same thing, but because I know that there smart guys in this list I thought of posting the question any ways hoping that some has a work around till the hotfix is available. MS Support will get back with me on Monday and they may have one of the developers work with me to fix the problem Manually and if this happen I promise I will post the solution here for whoever might come across the same issue. Thanks a lot guys and have a great day