Here is the thread from last year that dealt with the flickering inserts issue:

http://pinside.com/pinball/forum/topic/could-someone-with-a-x-men-le-check-something-in-the-setting-real-quick

The fix is an easy one, all you really need to do is separate out the black and orange wires on the harness (if I remember right it has white, red, blue, black and orange on it). Basically just separate the wires until you find those inserts don't flicker anymore.

Note that there are 3 possible harnesses that you might have to separate out the wires on (one long harness and two shorter ones). You'll see them when you have the playfield up.

I spoke with Pat a couple weeks ago about the same issue on my xmen, and the problem is in the jumper harnesses that go between the controlled lamp boards. Apparently the crimp or punch down machine used to make the connectors was not set correctly, and some of the wires are loose in the idc connectors. He sent me some new harness jumpers, and problem solved. There are 3 required.

good to know, I will have to check my machine to see if it does this .

Sorry to resurrect this thread but I have the same issue. Original owner on 123. I know it has been many years but do we have a contact at stern for the approved fix?