problem with crystal report 9 for dynamic multilevel grouping in postback of page

[virendra]

hi,
I am working on crystal report 9 in asp.net. I created multilevel
dynamic grouping in CR.
if page is load firsttime. and i am giving firstlevel of grouping or
whatever it's working fine.
but once page is loaded and i am changing the grouping options it's not
affecting the page. whatever the previous data in report that only is
showing. but it's exporting properly in excel file. So it can be a
problem of cache.

I am hoping anybody will have good solution for this.

thanks in advance.