I am buying a used Canon TS-E 24L II and searching the net for potential problems with this lens. Seems to be a very high quality made lens but one problem came up. The locking and adjustment nobs gets stuck. I am reading about this in Dpreviews, Fred Miranda, Flickr, Canon Community and also on Wikipeda. The knob stuck for no reason the user expalined, often the tilt adjustment knob. In some case Canon had to change the whole tilt-shift mechanism, expensive! Have not read an explanation why this happen and how frequent this problem really is. A known design flaw made by Canon or abuse from users?
TS-E users at Lula, have you ever encounter this problem?