Solving a 2.0 Toslink problem

I've got a Samsung 40" LCD TV, out of which I've been running a Toslink cable to an Audioengine D1 DAC, and then onto a powered Audioengine A5+ speakers (other speaker via speaker wire). This is not HT, but better TV sound via a 2.0 system. It works, but often the sound either doesn't come on or cuts out during TV startup, when switching over to a Patriot Media Box (USB), or when reversing a USB video and then going forward again on the media box. Since the cables are fine, I'm guessing there's something about Samsung's Toslink implementation that makes it unstable, or apt to cut out. Thinking of ways to test this, Plan A was to run coax, but neither the Samsung nor the cable box have it. Plan B was to run a Toslink from the cable box to the DAC, but since there's no sound with anything, I assume the cable box is looking for an amp on the other end. Beyond that, I'm in an area that I don't know much about.

My first thought is some kind of a DAC/amp combo, one where the amp is not headphone specific. Are there such things on the portable or lower cost market? Or should I be approaching this in a different way? Remember, this is a very modest set up, not high level HT. Thanks,
Check the toslink cable. That is the most likely cause of the problem.
I had problems with toslink before from various appliances kicking on. Do you have a power conditioner hooked up?
With Toslink it either works or it doesn't. No middle ground when receiving pulses of light. I would try another cable like these:
I've tried two Toslinks (2m), Monoprice and Silflex glass, so the cable is not likely the problem. No power conditioner.