Hhmph. Somewhere along the line I missed out on this–it appears that the period no longer requires two spaces after it. In fact, most prefer a single space because of computer and printing technology. It also saves space and time (trees and what, a nanosecond?) MLA also finds the single space acceptable, and for now, at least, will overlook us old buzzards who learned the double-space style.
Thanks to Miss Snark for bringing it to my attention.