ms charts with caching?

I put my implementation of mscharts 4.0 in a user control and it works great - just have to set a couple parameters and go.

I then went to cache the charts because some of them do some pretty intense work, but I get a broken image link when going back to a cached control. I am caching with this line in the ascx:

<%@ OutputCache Duration="28800" VaryByParam="*" %>

I figured the control would cache 开发者_开发技巧the temp image that the charthandler created but evidently not. Has anyone ever come across a solution to this?