Dennzio,
There are several possibilities.
1 - Static electricity/grounding. I don't know what your transport is but when I used a DI/O with a CAL Delta I would have small dropout's. It turned out the combination was sensitive to static in the house. I live in a dry climate and in the winter months it became worse. I ended up connecting a ground wire from the DI/O to the transport and that took care of the problem.
2 - It's possible that something is wrong with the digital cable. Not likely but possible. I would contact Wayne at Bolder Cables and discuss the problem. Try another cable if you have one.
3 - It's possible that something is failing in the DI/O. Again, it's probably best to contact Bolder.
4 - Another place to look is the CDP you are using for a transport. It may be on it's way out. Do you have another source to try with the DI/O?
luck,
Mike G.