The german Soundblaster FAQ states that you definetly need a pre-amplifier if you want to record from the line-in. I guess we can't do anything about it, at least the amplifier in Cool Edit Pro works.... :-( Greetings, Niels
Oh, well in that case you might want to look at a small 2 channel pre-amp like M-Audio's Audio Buddy or the like. http://www.midiman.com/products/m-audio/audibudy.php
Problem solved: just throw money at it. I picked up a new Audigy2 card, and I now have adequate levels thorough line-in. Thank you everyone for your input