When bitrate is set to 1x, my 24fps files have the proper framerate in the mov. When bitrate mult is set very high (Say, 2-3x), output mov has wrong fps metadata. The framerate is correct, but the display framerate in the mov isn't. Since I'm not using exact FPS (well, I wasn't. now I am! :P), this renders the files useless for audio syncing over long play times, because I have to set the fps manually and can't get the fractional fps right.
Now, you may be asking: "Why in God's name are you setting the bitrate mult to 2-3x?"
The answer is simple: the T1i's default bitrates are so ridiculously low that 3x the standard bitrate is about 40mbps.