Capture problem (Pinnacle/Vegas)

I hope someone out there can help me with this. I'm trying to capture video from analogue tapes (digital video is so much easier), anyway. on loan to me is a Pinnacle USB capture card and I'm trying to use Sony Vegas 9.0b to capture... only... to get this error" :The device "pinnacle 710-USB" could not be opened. Please make sure that it is turned on and not being used by another application or user" Any idea?

I use Windows XP.