Stop Driving Me Dotty With Those Full Stops!

I watched 'Big Brother' yesterday—yes, yes, I know!  I didn't plan to become hooked on the wretched show this year but, as the great quizmaster used to say, "I've started, so I'll finish."  Anyway, this little gripe isn't about the programme per se, but about a tiny, niggling incident in it.

In a task, one of the contestants had to pretend to be a psychologist or an agony aunt (or uncle in this case) and a large sign saying "Dr. Callum" appeared on screen.  And this, I'm afraid, is my little gripe.  I hate the use of stops after Mr, Mrs, Dr and such titular abbreviations—so much so that my fingers itched to reach for the Tippex and apply a dollop to the TV screen.

I've grown used to seeing its use by our dear American friends (and have tried in vain to educate them), but I haven't seen this in British English in very many years (until yesterday).

At school—a long, long time ago—my revered primary school teacher taught me that if the abbreviated word ends with the same letter as the whole word, no stop is necessary.  Thus Doctor becomes Dr, Mister becomes Mr and so on and so forth.  To abbreviate a word like Professor to Prof., however, a stop is permitted because f is not the final letter of the full word.

I only became aware that the stop (or should I say period for our friends over the pond) is used in this way in American English when I found my first American publisher and little dots appeared all over my very first manuscript.

"No, no, no," I said.  "This is quite wrong."

"It's our house style," she explained.

"It's my pet hate—it looks so old-fashioned and wrong.  Please don't do it to me."

"We'll compromise, just this once," she said.  Lovely lady.

When a different publisher—this time Canadian—signed up my next novel, the same thing happened and I took up the cudgel again.  Once more, they let me have my way.  It's a tiny victory, but then I suppose it's a tiny matter.

Does it matter to you?  Do you place full stops after abbreviations?  And does anyone know if 'Big Brother' has an American working on its production team this year?