Your problem is very similar to mine. I've been trying to get a replacement cable for almost 3 months now, but to no avail In the interim, to make matters worse, the tabs on the IDE cable head broke. So, I used some epoxy and put the head under some vice grips. I've had no problems booting since. I will probably end up making my own cable soon though. Check out the FAQ like the suggestion says, and look at the pictures to see what they mean about bad crimps.

Good Luck
-Ted