I don't agree. All the XP was available when I first tried the repair as a single operation. When I did it in 4 steps no additional XP was earned between steps – no time or game play ensued between the 4 consecutive repairs which were each done one right after the other??? I still have 445 experience after the four individual repairs.
You are right, it is a TMI issue. I had the same problem and took off TMI, and it worked again.
Ah, that was the missing piece of information that I did not know. Why is that? That probably explains why sometimes I cannot repair an item no matter what I do presumably because it is more damaged than 39 XP will repair even one step at a time.