TokBox not starting up reliably

I've been testing using my laptop to log in with a player account and my main computer to log in as a GM. I find that I don't always get the TokBox windows (and I can confirm that I'm logged into a different account by looking at the fog of war). I've had it work a few times with this setup, and just now it hasn't been working at all. I'm not sure if there's anything systematic, or if its just being generally weird. Both computers are using the most recent Chrome on 64bit Debian Linux. The main computer has a microphone but no webcam, and the laptop has a mic and webcam. I should say, both are connected with the same external IP in case that matters.

And, just to check, after both the player and GM are in the room, you've told both to allow video/voice?

Yeah. Right now I've got a single box set to voice only, which I managed on the main computer by toggling repeatedly between Video&Voice and just Voice. Absolutely nothing on the laptop though.

.. and now its working on the laptop all of a sudden.

So I've got a bit more of an idea of the form of the error. Evidently it has something to do with the disconnected debug message that you sometimes get. I generally have to load up Chrome, log in, get that message, then play some other webpage with sound, and then hit reload. That seems roughly to get things working. So it looks like this may be some sort of soundcard/sound driver issue, rather than necessarily something with Roll20.

Still, though, something to keep an eye on...