Did your connectors get dirty?
as for brands:
http://www.ramelectronics.net/audio-video/audio-cables/digital-audio-optical-toslink-cable/liberty-z500-thx-certified-toslink-cable-z500ntos/prodZ500NTOS.html

http://www.ramelectronics.net/audio-video/audio-cables/digital-audio-optical-toslink-cable//prodPOFT3MR.html

INFO:
http://www.arcelect.com/fibercable.htm

Link555 wrote: Did your connectors get dirty?....

Could be I suppose. It has only been disconnected a few times, but I suppose dust can get just about anywhere. I don't have one of those inspection scopes or the cleaning pads. (Is there any way to check this without a scope?) New cable is cheap enough and it will be good to have a spare. We'll see if that does the trick.

Isopropyl Alcohol 99% pure. Carefully clean the tips to remove dirt. Q-tips are ok, just watch the direction and try to not to damage the fibers.

You should clean the input ports as well. Delicate strokes, magnifing glass will help...

"Delicate strokes, magnifying glass will help..."

I laughed :P