I would like to add one thing to this discussion. There are 'creations' out there that contribute to the spread of the phrase "another thing coming".
For example, this song:
"You've Got Another Thing Comin'" - by the band 'Judas Priest' back in 1982 (no, this is not my type of music AT ALL, but I have actually heard the song and it came to mind when I was thinking about this discussion).
So it's because of stuff like this that I feel justified in my ignorance.
That, and I do have to agree with Paul... I've always heard it "thing" and that's what sounds 'normal' to me.
But at least from now on, I'll know not to correct it in any beta work I do.
