Few things to try:
Clear all caches, private data, etc in FF.
Update FF to the latest version which is 3.6
Update Flash to the latest version
Adobe - Adobe Flash Player
Reboot.
Let me know what happens. If something is wrong with the web server more then 1 or 2 people would be having this issue, pretty much everyone would experience it. Also when you are online there are other people online and they aren't reporting any problems. I want to try and exhaust all possibilities on your side before I start digging into the server side of things.