There is fraying where the cord meets the headphone jack which causes the sound to continuously jump from stereo to a single ear. I really enjoyed these in-ear headphones before this problem which is why I upgraded to the more sturdier SuperFi 5vi. Huge inprovement!

Ultimate Ears MetroFi 220vi work fine with the Google Nexus One. With some apps, you need to individually configure that the button will work as Play/Pause button. But this is an Android issue and applies to all headphones.