So, I was shooting a wedding this past weekend and all of a sudden, my 16-35L (v1) doesn't zoom anymore. It autofocuses just fine, but no zoom. Sounds like there's a gear or something rattling inside... so now it's an expensive prime. Anyone have any idea what's broken and what the repair might cost? Good thing the video team had an extra 16-35, because some shots wouldn't have been possible with my 24-70.