look at the actual HTTP that is being sent to the host and the actual (headers of the) HTTP response that is received. You can easily have cookie issues because, say, you think that the host received and stored the cookie but it did not ... whether due to a protocol problem or a typo or what-not on your part. "Trust, but verify." Never assume that you really know what is happening. You can spend many fruitless hours chasing white rabbits where you assumed that you knew what the error was, but did not.