I've not notice this until very recently but youtube (as well as other videos) appear to stutter ever so often in Firefox. Other times, I see no stutter at all. It' very random as I could watch other videos and not notice any stuttering at all. Upon some googling I've found that this is a well known issue with one guy putting up a youtube benchmarking test to show if you are getting it or not. You can get it here. This isn't a "precaching problem". You can preload the entire video (IE: red line fills up) and it would still stutter at times. Which draw my attention to what actually could be causing this. Has anyone else noticed this or found a solution to this problem? Again, this seems to be most evident with Flash's most recent official update. I've not seen it nor knew about it prior to that. The most recent build is 10.0.45.2 released on February 11, 2010. I wish I could go back to the previous build.