Willona states her ex-husband is named Alvin. In the fourth season he is named Ray.

i THINK IT WAS JUST A MATTER OF THE WRITER'S NOT PAYING ATTENTION TO DETAIL.

Willona states her ex-husband is named Alvin. In the fourth season he is named Ray.
Regarding GT, you will notice the writers didn't pay much attention to detail. Apparently as an audience, we didn't either, until GT began airing in syndication...which gave us the opportunity to chop, slice and dice the shows. The writers also were changed, so the new writers were not either aware, or didn't care to find out the original info that was already stated.