I need to do some peeking around this a bit before I start talking but one alternative would be to have a banned/allowed extensions array and whitelist or blackalist accordingly, hence allowing all .movs if admin requested. This could be used in conjunction with getID3 to override problem areas like unsupported formats while maintaining getID3 functionality. . .
Anyway, I haven't had a chance to look into the issue but that's the first thoguht that pops into my head. . .