Since a Firefox update can't remember which my spell checker has been naffed up it will underline it if it's wrong but on right click it doesn't give me the correct guesses.

Anyone else had this? I've put up with it but now I'm annoyed.

Is there not an updated version of the spelling check plugin?

I've found a spell checker but you have to check when you finish, the other one I think was built in. I believe it's the Mac OS X one perhaps not integrating with Firefox.

Install the British Dictionary for Firefox and set it as your default, that will check the spelling for you.