Parameter Change and Report Clears

When I change the value of a parameter the report is cleared on a post back to the server and I have to click on the View Report button to see any results.  Is there a way to either not post back to the server when the parameter is changed or automatically post back and retrieve the new results

I found this link below here and it sounds like I am out of luck since both of my parameters are dates with functions to define them.  I have tried changing their order with no luck.

 http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=284284&SiteID=1

Does anyone know if this is an issue without a work around

Thanks!