In an ASP.NET 3.5 website we are noticing that the back button is not working properly. If the user does several postbacks (say 10 times), and than starts pressing back button - the back button gets disabled before the user gets through all the pages. The site does not use AJAX.net.

I can reproduce the issue on IE 7 and 8 almost always. The problem seems to be with some sort of limit IE has on History Cache for a given tab/instance. In the tests I did the post request to the server are large - around 83k, and the responses are are round 300k. It seems that with these request sizes the history does not hold more than 4 items. The moment I get to the 5 post, the first item i had selected is dropped.