Can you list all the options in your 'Recording Properties', if you don't have Wave or SMix, what do you have? I know my Audigy 2 LS has a 'What U Hear' option, which is the one I have to use if I wish to record sound.
After checking them and displaying them in the 'Recording Mixer Panel' where you can adjust the volume, you also have to check the 'Select' checkbox below the slider of the input you actually want to use. This is because you can't record from 2 inputs at the same time, after doing this, you should be able to see the selected option in FRAPS:
A quick way to check which one works, is to select one of the recording options and then quickly open Sound Recorder and record a small snippet of sound while some music is playing in Winamp or WMPlayer, etc. If you hear something when you playback what you've recorded, it should work in FRAPS as well.
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