Where did you see that it should be 6050A? I've looked on Google and couldn't find a NEC 6050A burner.
It's several years old. I got the number from my SYSTEM TOOLS>SYSTEM INFORMATION lists. When I was trying to figure out the 'not closing' problem, I checked for updates, and did ieventually install one, somewhere in the middle of all this. I just checked the system info list, and now it is, in fact, listed as the new model. So that solves that part, but not the closing problem.