mine are still on after 3 years and 20000 miles. they are screwed in, so unless the plastic threads are knackered, they shouldnt come undone and fall off
I agree with stevecbr on this one, mine are tightly screwed in from the underside (MT 0-9) so it is difficult to understand why yours keep falling off, even if the plastic thread in the clear lens is stripped each time you fit a replacement it has a new thread.
Thanks for replies, the screw is intact, its the lens that's broken clean off, leaving the screw and that part of lens intact, I have replaced again and put some thin black electrical tape on it now, looks ok
Mine went in for 6k service... when I went to pick it up I noticed a cable tie holding the front right lens on... so back in I went.... service guy came out, "Oh Yes! Funny that was, it just fell off, never seen it before", so... why didn't you put a new one on... my mate came here a few weeks ago and had 2 replaced under warrenty... mines still under warrenty.... he took one off a bike in the showroom...
So yes I think its an issue beyond a certain age, mine is 3 at end of June... its kept garaged too.. maybe the glue is just shit..