Right, an explanation.
We’ve been testing a new version of the site for a couple of days, which I’ll talk about in more detail when it goes live. STW applied the upgrade earlier today but something went tits up* during the migration. As a result, rather than displaying usernames the forum started displaying the “name” field you can edit on your profile. Hence “munrobiker” became “Munroe Biker” and so forth. When the problem was spotted (there were a couple of other glitches too) the site was immediately rolled back to the previous version.
Tom believes he now knows where the migration went wrong – there was a chunk of code which didn’t copy across completely – so pending a few more tests he’ll likely try again presently.
(* – apologies for using the technical term here)