This is a well documented problem with Ulead. It is not compatible with windows 7.
Do not know why it does it in Debut? It is usually good. Try the usual audio fix. Bypass the USB audio altogether.
Purchase a "3.5mm Stereo Jack to 2 x RCA" adaptor. You can get them for 73p inc delivery on Amazon
http://www.amazon.co.uk/WE11130-Adaptor-3-5mm-stereo-sockets/dp/B000L9C3GY/ref=sr_1_5?ie=UTF8&s=electronics&qid=1271193386&sr=8-5Take the 2 audio outs from your games console/vhs player and insert into the adaptor. Insert the adaptor into the "line In" input at the back of your pc on the sound card.