Hi, The problem is when the return URL code is generated and appeneded to the URL it causes and HTTP 400 error in IIS because it uses an ‘&’ (ampersand) in the URL. IIS 6 and 7 do not like that, and causes the the HTTP 400 error. If I manually replace the ‘&’ in the URL with a ‘?’ the URL again works properly. How/where can I modify how the return URL is generated? Thanks!