I recently went through the RA replacement process for my UE900. This is obviously a known problem for this earphone and you should ask for a replacement from a later batch. I actually got a full exchange from my retailer for something else because I do not want to have the same issue arise a few months later, or worse yet have the plastic shells simply fall apart on me.
I honestly find it INCREDIBLY disappointing that these earphones have this problem, that the management at Logitech KNOWS that they have this problem (it's been confirmed in Amazon reviews that upper management at UE monitors the reviews and responds to them) and yet there are bad earphones still floating around in retail channels with no official recall or response.
This is absolutely shocking given the cost of the earphone. You would think that with these problems, Logitech would, at the very least, issue an official response: all UE900's from batch number XXXX are fine. Not a peep.
I made a big deal about this in
my review of the UE 900 but now I honestly think even talking about the sound of this earphone is an unfair endorsement given the quality control of this earphone. No matter how good it sounds, I would never buy an earphone after reading through a thread with comments like this.