I've been having a similar problem but with HTTP not HTTPS, therefore the IE problem mentioned above is not the cause (according to MS it only affects HTTPS).
Scenario 1: Request content length is -1, QueryString parameters available, form parameters not.
Scenario 2: Request content length is a positive number, QueryString parameters available, form parameters not.
Scenario 3: Request content length is a positive number, QueryString parameters available, and only SOME form parameters are available.
I managed to solve scenario 1
. It was caused by the user clicking refresh after getting the IE error 'The page cannot be displayed', because there is no longer a form to post. (FYI the IE error was caused by a faulty Cisco cache engine).
However, I'm still getting scenario's 2 and 3.
It seems to be a random problem that is only occuring in our Production system. 99% of the time the request from this page works fine. I can't replicate it in our dev/test environments, therefore I can't put a sniffer on to diagnose it. I can't put a sniffer on Production as the volume of data would be astronomical.
I've checked the request's Content-Encoding and its coming through as ISO-8859-1, which is what we set in our JSPs. I've checked the referrer and the user is coming from the page that does contain the correct form.
I've tried everything I can think of
Has anyone had this variation of this problem? If so, any ideas?