Firefox Flash Playback Mystery

Recently I have been noticing that flash animations on Firefox have been very rough. They seem to be jerky and appear to flicker when objects are moving. I know this is an issue isolated to Firefox as I have tested in IE and Safari. I don't recall always having this problem so it leads me to believe it is an issue related to the newest release (I am using 3.5.8) or it may have something to do with a plugin I have installed. Either way it is a mystery to me. If anyone else has had this problem let me know. Especially if you have a solution.