well the PS/2 keyboards have a limit that is for sure, but I have no idea how the usb keyboards are handled, so - who knows ^^
After giving it some thought from programming side of view, actually I think it could be game related, but since it's probably part of some binary file, not those easy to mod txt's, I think it's better that the dev's don't touch it (who knows what other bugs they'll create ^^)