I use a Url Rewriting a lot and ran into this problem very offen. There are multiple solutions to this issue and basically we would be manipulating the “post” action of the web page.

Here is a link that talks about a more elegent approch to solove this problem, Postbacks does not work with URL ReWriting.

http://weblogs.asp.net/jezell/archive/2004/03/15/90045.aspx

EDIT: please see my new entry on this topic http://blog.budigelli.com/index.php/2007/06/14/aspnet-url-re-writing-and-postback-problem-solution/

- Thanks,