Is it possible to use Skype across a terminal server client connection to a WinXP machine?

I have Skype set up on the WinXP machine, but the Skype call testing service does not pick up any sound from me, and seems to be saying it does not detect a sound card.

Ubuntu is 10.04. TSC is using RDPv5.

I am not sure if the WinXP machine has a sound card. Is this a problem?

I do get sound from the WinXP over my Ubuntu machine's speakers, such as from the start up sounds, and connecting to a news clip on a tv station, also I have used webinars over the TSC connection.