Although I haven't tried it, I suspect that could be "solved" by adding at the start of the plugin,
PHP Code:
$vbulletin->GPC['subject'] = strtolower$vbulletin->GPC['subject'];
But that in turn creates issues by changing acronyms to lower case (HTML would become Html; AOL would become Aol). It would also potentially conflict with the "small words" feature, such that a small word at the start of a sentence would be uncapitalized.
I think a nice addition to this would be to include a list of common acronyms that will automatically be capitalized (as above - for example, so "aol" becomes "AOL" instead of "Aol".) I suspect that's an easy change to make, but my programming skills are woeful.