New diff balls and rings...but still VERY notchy!

[Fiddybux]

I'm confused at this one.

Just rebuilt my X5 diff, and new ceramic diff balls and diff rings, and when tightened the diff is unbelievably notchy.

I haven't replaced the diff gear itself, but it looks okay, and I've rebuilt it several times using the same diff gear, and it's been okay before.

Any ideas? Is the diff gear that is warped / melted / worn?