The band that clamps the air filter mount into the boot broke yesterday on our '06, leaving the air filter and mount laying in the bottom of the box. Of course, it sucked a bunch of dirt. I've never had this happen on previous year bikes. According to Yamaha's parts catalog, this clamp is the same on YZ250F's and 450F's from 03 through 06. Upon inspection, it appears that this clamp was overtightened and twisted, probably causing this failure. I have never tightened or had this apart, so it had to have happened before it left the factory, or before I recieved it from the dealer. Once any damage is corrected, you can be sure that I will silicone the mount and boot together, as well as safety wire aroung the clamp to prevent this from happening again. Our 06 250F will get the same treatment.