Issue with WP Symposium

I spend a lot of times with WPS (Symposium) people and just found out that this theme is having an issue with WPS. The only issue is that attach file button which I believe uses flash is not working. More specifically, when using Chrome, it actually works but it will not do anything on FF or IE browsers.

Have you seen this issue before? Any thoughts or way to resolve it?

Thanks for your help in advance