Currently Scrivener autocapitalizes after “vs.”, and of course that’s usually unwarranted. If that could be fixed it’d be much appreciated.
In British English, you would not necessarily follow “vs” with a full-stop, because “versus”, the word abbreviated, ends in an “s” (just as in British English you would not necessarily follow “Mrs” with a full-stop). So by adopting British English and omitting the full-stop you could solve the problem you’re facing. In US English, the usage is different; I believe that you would follow “vs” with a full-stop (or period). (There may be exceptions to this distinction as usage increasingly crosses the Atlantic.) However, I’m not suggesting that that is the reason Scrivener’s text engine is capitalising the following word: I suspect that it may simply be that the text engine’s list of abbreviations ending in a full-stop that do not require capitalisation immediately afterwards could in theory be quite long and is probably not comprehensive.
I don’t think Keith has any control over this; it’s probably a built-in Mac OS X text kit feature, much like the dictionary and grammar checker. But there is a solution if you’re willing to modify your habits.
Since you’re relying on Scrivener to auto-capitalize, you could rely on it to add a period after every instance of “vs” that is preceded and followed by a space. In the Compile window, go to the Replacements section. In the Replace column add a the vs with spaces before and after it. In the “With” column, enter a space, followed by vs., followed by a space.
Now get out of the habit of typing “vs.”, knowing that when you compile, it will add in the “.”.