Apple and grammar

Every once in a while, something about grammar will just pop out at you. Testing OS X 10.5 Leopard recently, a window popped up with the statement "none of your preferred networks are available". Now, as I understand it, the word none is equivalent to "no one" or "no single instance of", which is a singular term - and should therefore be paired with "is", as in "none is". So wouldn't that be "none of your preferred networks is available" instead?

Doubting myself, I turned to Google and found this document, which says that "conservative speakers insist that it should always be singular" but the other 99.95% of the population uses both singular and plural depending on the circumstance. I love their use of the term "insist", by the way. Adds a bit of color to their true feelings about the matter.

The upshot? I would have copped out with "none of your preferred networks can be found".