Hi,

Try referring to this link - http://msdn.microsoft.com/en-us/library/ms156511.aspx if you already haven't.

 A particular section caught my eye and reminded me the basics before deploying anything further. It was:

"Reporting Services does not return an error if you are using a browser that is incompatible with the default HTML rendering extension. In many cases, Reporting Services suppresses features that do not work. In other cases, the feature may be available to the user, but does not function correctly. Each browser type handles report features differently. Before you deploy a report, you should always test it in the browser you plan to use."

And secondly try and republish your site after you have made the changes in the reports. Sometimes old compiled files and cache are not cleared and hence become a problem. So even if the problem is resolved on the code or report designing side it does not reflect the changes.

Let me know if this has helped or not?

Cheers