Word Clock? ...click noises on digital output

Hi,
i'm trying to record single tracks of a song
that i made with my MPC 2000 XL ...on to PC.

I'm using the digital output Jack on the MPC...
thats going into my Terratec DMX 6fire soundcard
(koaxial digital input cinch).

Problem: in the files i record on the PC i hear tiny
little click noises. It seems there is a problem with the
Word Clock signals ~ digital frequency interferences.

At one point I thought i found a solution for the noises
problem when i sync'ed PC and MPC via Midi Clock
...the noises were gone!
But i then i realized that the timing of the recording got
slightly messed up. So the single tracks of the song were
not 100% in sync anymore at the end of the song.
Seems Midi Clock is not really precise.

Anyone got a solution for this?
I just wanna record digitally... and get rid of the noises.

Is the MPC 2000 XL actually able to receive or sent
Word Clock signals?

Just use your analogue outputs until you sort out the problem?