I currently own two pairs of Grado headphones -- Alessandro MS1 (purchased in 2007) and Grado SR325is (purchased 3 weeks ago) -- and in both pairs, my left earcup has fallen off the little metal peg that goes into the black plastic connector on the cup housing.
Each time, this has happened just a few weeks after purchasing the headphones. With the MS1, I just used some Gorilla Glue at the connection point and although there's a little overflow, I let it be and just trucked on. But now with my new 325is, I can't believe I'm having the same problems 4 years later. (Well, I guess it shouldn't be that hard to believe since the cups are indeed heavier....) But still, this should not be happening with headphones in this price range.
I like to baby all of my belongings and my 325s have only been on my head or on a headphone stand since I bought them. And yet I put them on today and have the left earcup fall out! And I try to put it back in and the connection is so loose. I'm not going to lie, I'm really disappointed that I've tried two different headphones with the same results of the cups falling out.
Here's a pic of what I'm talking about. [Disregard my bright blue gym shorts ]