You mean "240p" right? (I've never seen a "250p" option)
I presume the speed button means you are using the HTML5 "trial" option? I've watch Youtube clips today that had a 240p option with the default Youtube Flash (FLV codec) video player (I'm not opted into the HTML5 trial at the moment).
P.S. Just checked back to Wikipedia's handy table of Youtube audio/video encoding settings and it says that they don't encode 240p video for the WebM codec (this is the codec used under most browsers when using the HTML5 player)
See:
http://en.wikipedia.org/wiki/YouTube#Quality_and_codecsAlso note: you can opt-in/out of the Youtube HTML trial from here:
http://www.youtube.com/html5
Yes, I meant 240p. It does seem like that HTML trial was the problem. I didn't even know that I was using it but opting out of the trial on that link does seem to have solved the problem. Thanks.