Strange Android Customer Error

My app had been chugging along fine on the Android market until last night when it was reported a customer found an error. The customer must have downloaded the latest version of the app because he tried to use it again with the 开发者_如何学Golatest version and the error came back.

I looked at the stack trace of the error and found it was caused by a NullPointerException when passing information between two activities, namely with the onActivityResult() method.

I checked the code and can't find what could have caused the error. I tried to figure out what steps the user took to get the error, but found nothing wrong, on the emulator Android 1.6 /Android 2.2 and my own phone (Android 2.2). I couldn't find any problems no matte rhow much I tried to crash the system.

Another thing that is strange is that the particular onActivityResult method is called a lot in my app. So it is odd that only one user has reported problems.

Also, it says the user's platform is "OTHER". I don't know what device that could be.

So my questions are: 1) Could this problem be an issue with the user's device and not my application? 2)What to do when you cannot find the cause of a crash?

1) Yes, they may have a custom ROM; they're known for doing things like this.

2) Unless you can reproduce it, you [probably] can't fix it.

Can you contact this customer? If not, there may be nothing you can do.