Android app bugs/errors only on certain phones

I've released an app about a month ago now, and it works as it should on my Desire and presumably on a lot of other phones. However it is also receiving it's fair share of 1 star ratings with comments that say that the sound simply doesn't work. Given that this is an app to play开发者_运维百科 sounds and alarms that's a pretty major problem.

Thankfully one user emailed me to say it didn't work for her, so I at least know one model of phone it's not working on. However I have ZERO idea how you would even begin to work out why code isn't working on a particular phone. If the code is written as per the android docs, and it works in the emulator and on my own phone, I can't begin to work out where to start fixing this.

Any ideas?

If you are contacted by a reasonably advanced user, they could either install a logcat app such as aLogcat or access logcat output over USB if they have the SDK installed, and mail you the output of the phone logs after running your app. It might have some hint as to what is failing.