I'm using Chrome on Windows and, although there's a slight delay in getting the InfoWindows to load, I can select text in them now.
Chrome, you say? Hm. I just fired up Chromium, and indeed, I can select text in the InfoWindow now. Firefox is still a no go, though.
Ah well... Guess I'll be using Chromium now... :\ (Meh, GMaps is every-so-slightly faster on it anyway?)
Thanks again for making the fix, theFXexpert!