Okay, I know that Boom-Boom is a low-end X-man HC fig, but I need a SERIOUS fan to answer this question:

Why did Boom-Boom Change her name to Meltdown? The people in my area that read them say that it had something to do with Sabretooth, but nobody knows any more than that.

What happened?!?

I just happened to re-read the povital issue of this story the other day. Sabertooth had been captured by the X-Men, and Boom-Boom took it upon herself to take care of him, thinking he was helpless. Turns out he was shamming, acting all zoned out when in reality he was scheming the whole time. Sabertooth, bound in the mansion, is confronted by Boom-Boom, he calls her white trash or something like that, which infuriates her, she throws a time bomb at him, only managing to free him from his bonds and making him mad. Before he can fell her, Psylocke steps in and takes the fight to 'Tooth. Boom-Boom, her powes exhausted, watches helplessly as 'Tooth guts Psylocke and escapes.

Yep, that's pretty much the gist of it, although why they gave her Jubilee's dial, I have no idea....

Ah, okay - I didn't know if Sabretooth did some REALLY bad stuff to her, or what

Meltdown and Jubilee while having different visual looks to their powers, have damagewise and other, the same type of powers. Tabitha changed her name from Boom Boom because she felt it was a little kid's name and wanted a more mature codename.