Hi Tom,
Thanks for taking the time with this one.
I am sure it's something to do with just settings. There was a thread about it
a few months ago. "Webmaster at Kracked Press" had a good answer but i can't
find the thread.
I'll have a look.
I don't know if this is it but in
Tools - Options - LibreOffice - Paths
is AutoCorrect set at something like
/home/username/.libreoffice/3/user/autocorr
Yup. Although there are no files in that directory. Perhaps that's not important.
Also in
Tools - Options - LibreOffice - "Language Settings" - Languages
there are 4 drop-downs. The top one often reverts to "English (USA)"
I can't get it to say anything else. Where can a reset a language to give me more options for
this dropdown? I've reset the locale & language in Fedora, that doesn't seem to do it! 
But i
think they all 'should' be on "Default - English (UK)" ecept currency which
'should' by "Default - GBP"
Default doesn't seem to be an option, they're all countries & currencies. Mine is set to GBP.
In the top box of the 3 boxes in
Tools - Options - LibreOffice - "Language Settings" - "Writing Aids"
I have "Hunspell SpellChecker" ticked.
This seems to be the crux of it. Hunspell doesn't appear in that box, and I don't see any way
to add it, from this dialogue anyway.
In the middle box i have 4
"dictionaries" ticked
standard [ALL]
soffice [ALL]
technical [ALL]
IgnoreAllList [ALL]
I have added a couple of dictionaries, but I have these you mention too.
In the bottom box i have ticked "check spelling as you type" along with most of
the rest of them except "Check words with numbers" and "Hyphenate without
inquiry".
Yup, pretty much my setup too.
I have CC'd the message directly to you in the hope that you get the attached
screen-shots that way in case they look completely different from yours.
Nope, not got that.
Im haste
Mark Stanton
One small step for mankind...