I recorded an MM8 speedrun recently. It was running in a window though.
This open source software was used for recording (v0.6.7 at the time): http://sourceforge.net/projects/screencapturer/files
It's not as simple to use as a lot of recorders, but if your soundcard is like mine, it doesn't have a "What U Hear" option for recording. The above software provides a loopback setting which allows recording of whatever is playing from the speakers, without needing any extra cables. Resulting file size is huge as there is no compression built in, but quality is perfect.
Also, disabling Windows Aero made a massive difference to recording speed.