Digi 002 PT 7.4.2 SPDIF problems

[theworks]

Anybody have any idea why my system would be inconsistent with picking up a SPDIF signal from my mpc 2000XL/ Sometimes I make a session for a quick 2 track and it picks up the stereo SPDIF signal. Other times I start a session and the input area says SPDIF na (in italics). After checking preferences and starting a new session it will often later give me the option to select SPDIF for an input but won't detect any signal. Any advice would be greatly appreciated, I understand most of the time this type of stuff is usually user error.