audio capture in the settings?? Im sure you will have though.
next thing is to right click on the volume control icon in the system tray. click on "open volume control".. then click on "options" click on "properties" then select the "recording" spot.
you can then see if the line in has been enabled with a tick in the box. at this time you can also adjust the recording levels, I have my line in set to its highest level.
I have the dc10+ card and have had a problem with audio capture to, what I described above sorted it for me.
Hope this helps...cheers Lixdexik.