For some time I have been experiencing a bug with WordPress not showing the Page Templates dropdown on the page editor. I have been able to resolve this by deactivating and reactivating my theme. Not sure why this worked, but it was suggested in threads here and sure enough it works.
Now, I have upgraded to WordPress 3.4 and everything else being the same but now the technique above no longer works to restore the Page Template dropdown. I have no way to use page templates now at all.