If you are using the ATI TV Wonder card and are having problems with the audio dropping out or not being heard at all try this...

Don't use the audio connections on the purple dongle. Plug your RCA cables in to an apater (get one at radioshack) and then plug directly in to your sound card. I did this and the audio showed up each time. Even after closing and using different capture apps. You will probably need to set your capture apps to "line in". Also have your control panel audio options open as you might need to unmute a few things. Hope this helps.

My system:
XP Pro
Athlon 1.2 mhz
700(ish sdram)
Gefroce 2 GTS