Ok. Bought an installed 1.5 upgrade so that when Roland from B4 arrives to recalibrate my CRT projector in 2 hours I have the latest software working. I have Windows ME, M-Audio Delta Dio at first with the drivers which came with it. The system worked perfectly before I upgraded. Upon running TheaterTek 1.5 for the first time - no sound. Then discovered the audio settings and changed from Prologic to Sp-Dif. Then got the 5 second delay problem. After following advice on the TheaterTek forums I downloaded and installed the M-audio 3.1 beta drivers and now I have no sound at all out of any of the options. If I choose default Direct Sound or WaveOut, after restarting TheaterTek, the sound has reverted to prologic. I have also tried changing the options and rebooting and still no joy. I'm bloody furious at this. And the clock is ticking before Roland arrives. Someone please help !!!!!