[ Closed ] pun_bbcode buttons have disappeared

I spent about an hour going through archives last night and found a couple of people with the same problem but none of the suggestions solved the problems.

To sum up

- I've downloaded latest version of pun_bbcode
- I've refreshed the forum cash
- I've refreshed the extension hook
- I've disabled other extensions

But I still don't have any BBCode options.
Apparently, just one of my forum users says she can still see and use the options but nobody else can out of at least a dozen testers.

Any ideas?
Thanks in advance for any help