On the high setting it records around 12fps, on low around 17. Any help appreciated. In other GB roms I've had some success by switching kernels, particularly to Pete's (though it was a different video recording issue - jumpy video). Thought I'd hold off in case I missed something. Thanks!
18.104.22.168imoseyon-0.1 kernel (came with the rom)
Overclocked to 1100 using smartass