Yeah, i've seen it at more than one of the plugs, atleast 3 of them are doing it. I've done all that I can think of to try and stop it but nothing has worked.

 

If it is arching at the plug(s), then the boot(s) for the wire(s) are either not on all the way or they are bad. I think you said you replaced them, but if you pulled them off a few times, you may have cracked the boot slightly without knowing it. If they weren't on all the way for a while at first and were then put on all the way, then they probably burned up and are shot. Regardless of what happened, that is the problem is. Try a new set of wires; it's worth the $20 to rule it out or fix the issue.