mod security turned on, but having some issues

[b k <bk4web@xxxxxxxxx>]

Hi all,
The web application which I am currently supporting incorporates reports generating functionality using Java Reporting Component which worked fine on WebSphere App server and also Apache 2.2 before turning on the mod security configuration. The app used to generate reports in a PDF format on both IE and Firefox browsers pretty well. Now that the mod security config is turned on, reports could not be generated properly on any browser. I have these issues:
On IE: I get the File Download dialog with the warning "The file you are downloading cannot be opened by the default program. It is either corrupted or has an incorrect file type." Instead, the report should open Adobe Report automatically.

On Firefox: All weird characters show up on the browser - looks like encoding issue.

When I tested the above issue directly on the App server, there is no problem which led me to suspect that Apache 2.2 configuration is the CAUSE for this ISSUE.

Please help ASAP!!!

Thanks!