MDI said it was possible to use Fraps and I myself use it for my
recordingsYou just have to change the video settings under Mugen.cfg
Under the drawing mode section it has to read something like this
;Drawing mode
;Choose from Normal (fast) and PageFlip (less image "tearing")
BlitMode = PageFlip
;Screen rendering mode.
;System - default SDL rendering mode (e.g. windib in Windows)
;DirectX - DirectX 5 renderer
;OpenGLScreen - hack that allows window resizing but could be slow;
RenderMode = OpenGLScreen
Change the drawing to PageFlip and the rendering to OpenGLScreen
Although it screws up fullscreen mode since the sound won't play anymore after I press Alt+Enter
Also try a smaller resolution, HD will just lag like a mofo depending on stages and chars.