"must've" -- not correct?

[nq:1]Why does my spellchecker question this[/nq]
What is "this"?
and other contractions like
[nq:1]"must'nt"?[/nq]
Mustn't is spelled mustn't, like all the other n't abbreviations.
Posters should say where they live, and for which
area they are asking questions. I have lived in
Western Pa. 10 years
Indianapolis 10 years
Chicago 6 years
Brooklyn, NY 12 year

[nq:1]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
Because it's not a very good spilling chucker? Or are you able to educate it?
With best wishes,
Peter.

Peter Young, (BrE), Consultant Anaesthetist, 1975-2004. (US equivalent: Attending Anesthesiologist) Now happily retired. Cheltenham and Gloucester, UK.

[nq:1]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
"Must've" isn't an actual contraction. The correct application is "must have."

[nq:2]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
[nq:1]"Must've" isn't an actual contraction. The correct application is "must have."[/nq]
If "must've" isn't an "actual contraction" of "must have", then what the devil is it, actually?

Cheers, Harvey
CanEng and BrEng, indiscriminately mixed

[nq:2]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
[nq:1]"Must've" isn't an actual contraction.[/nq]
You'd better tell the author and publisher of this book, then: http://www.amazon.com/Mustve-Been-Something-I-Ate/dp/0375727124

It Must'

[nq:2]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
[nq:1]Because it's not a very good spilling chucker? Or are you able to educate it?[/nq]
Occasionally, my spell checker also allows something which I don't recognise as being correct. I put it down to the fact that, at some time in the past, it was flagged up as being a possible mistake, and I accident

[nq:1]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
I suppose it shouldn't've done that.
kt.

So I went to buy a watch, and the man in the shop said "Analogue." I said "No, just a watch."

[nq:1]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
Oops - meant MUSTN'T. Sorry to confuse.

[nq:1]On 17 May 2009, BMCT2010 wrote[/nq]
[nq:2]"Must've" isn't an actual contraction. The correct application is "must have."[/nq]
[nq:1]If "must've" isn't an "actual contraction" of "must have", then what the devil is it, actually?[/nq]
A visual representation of slurred speech.

Posters should say where they live, and for which
area they are asking questions. I have live

[nq:2]Why does my spellchecker question this and other contractions like "must'nt"?[/nq]
[nq:1]I suppose it shouldn't've done that.[/nq]
LOL Very good.
My spell checker offers to change shouldn't've to shouldn' t've or shouldn't 've or shouldering, among others.
[nq:1]kt.[/nq]
Posters should say where they live, and for which
area they are asking questions. I have lived in