Flash .fla framerate seemingly affects .flv video playback performance in IE

I've been doing some work using the FLVPlayback component to make a generic video player application, but noticed recently that video playback performance was choppy within Internet Explorer (6 and 7) compared to Firefox.

After a quick search I found this forum post, and after changing the framerate of my .fla from 12fps to 24fps I found performance within IE to be comparable to Firefox again.

I hate these "it shouldn't be the case, but is" rules with Flash sometimes.