When troubleshooting why something doesn't work, the cable is usually the first thing I try to elminate as a suspect.
You're using a laptop. Bring the laptop over to the receiver, use a shorter cable, and see if it works. If it does.. bingo. Your 100' $25 optical cable is the culprit.
The fact that other things work with the cable is completely irrelevant. Every diode and processor is going to have a different minimum functional level.