Flash games aren't working

Browser: Firefox 4
OS: Natty Narwhal (aka Kubuntu 11)
Computer: Toshiba Satellite L645D-S4025Youtube/Viddler videos work just fine. As for Flash games, it either a) doesn't load in the first place, or b) loads to a certain point either at 10%, 65% or 100% before it crashes. How do I fix this? I know there's a Flash update I need to get, but I don't know how to do it (I can't figure out exactly what to put after "sudo apt-get install"). If you know, that might work.Thanks for answers.

Update to Firefox 7 BETA for starters
Go to filehippo and install the update checker. Maybe you need to update flash

Replying to #2

Firefox 7.0.1 is already out. It's not beta any longer.

Not updating Firefox. Anyway, as it turns out, I think it's just the particular games anyway, maybe they're Shockwave.@mods: You can lock this now.