[linux-audio-user] sounblaster live platinum and full-duplex recording (noisy)

recording seems to be working OK but: in audacity when I record the track it sounds OK however if I generate click track and record then (the click track is playing while I am recording) the recording is really bad (noisy, low quality). I vaguely remember something about full-duplex on sounblaster not being very good, i.e. there's something wrong when using it but don't remember what (bitrate being forced to be very low or something along those lines). However I can't find any information on that subject now (I tried google and creative site), does anybody know details and/or have some pointers to relevant docs? system: debian unstable, 2.6.5 kenrel (with alsa), sounblaster live platinum (with live drive). TIA erik