I had been using a simple sound card interface (Donner, works fine) with my TS-480, but wanted to allow normal computer sounds to go to the speakers and have seperate sound card for digital interface, so I got a SignaLink USB.
After installing it, I fired up JT65-HF v1.0.7, changed the setup to point to the SignaLink (USB Audio CODEC), and then it started faililng with the
pa error invalid number of channels could not setup for stereo input
message on my WinXP machine.
I was messing around with it, and went to Control Panel / Sounds and Audio Devices , clicked the AUDIO tab, made sure the regular sound card was selected for normal sounds (SoundMax in my case), and then saw at the bottom of the AUDIO tab that "Use only default devices" was checked. I unchecked it, went back to JT65-HF, re-did the SETUP change to point to USB Audio CODEC (the SignaLink), and then everything was fine. I'm not sure, but I think that unchecking "Use only default devices" fixed the problem, at least for me.
I don't know if that helps anyone else, but it did the trick for me.
73, Dave N0RQwww.powerlinenoise.com/n0rq/