Karl,
I'm sorry to say but it's gotta be how your rigging it.
As Ian said maybe it's rubbing on the sidewalls of a block.
But like I said, we have used 4 spin halyards out of excel matrix with no problem and have other guys that have used the same.
I've also used the fse racing sheet and will probably be going back to that when it's time for a new one.
When you figure it out I'll make a new halyard for you since you cut up the other one I made.
-Todd