Strange firefox bug with input field?

I’m using firefox 3.5.2 and I’m getting a really unusual bug when using the input field in flash. For some reason if hit the return key or use any of the arrow keys it will fire off twice. For example if I hit return it will create two line breaks, or if I hit the right arrow it will go over two spaces. Has anyone else run into this issue? I’ve tried it in ie8, chrome, and safari and I don’t see the same issue.