USM motor sticks?

Hi All,
I was browsing another board on lens reviews and read a comment that the user had to send a particular canon lens in on two occasions because "the USM motor had gotten stuck due to disuse for long periods"
Say it ain't so!!
really? Does that happen?
Share your comments/experience please.
Cheers
PP

Yes, I think that is a possibility. On a couple of occasions I've noticed that my EF70-200L /2.8 will hesitate before acquiring focus, it hasn't actually locked-up but I suppose that it could sometime in the future. That lens is an older model that I've had for a few years now.

Also, an EF20-35USM lens that I owned a few years ago had to be serviced twice, in the time that I had it, for focus motor failure. I'm not sure that you could say it locked-up it more or less just stopped working in the middle of a shoot.

These USM focus motors definitely do have a lifespan of a certain number of activations, I'm not clear on the exact number, somewhere in the range of 20,000 or so, I think.

Cal CPS432