RH51 system. System kernel not changed from install. SB 16 soundcard and driver. Works great for playback. multitrack software. I can't play and record at the same time. SB16 basic box says it supports duplex. If I cat sample.au > /dev/dsp there is no complaint. If I cat sample.au > /dev/dsp1 I get "dev not configured" How do I get duplex support?