How to debug this crash (Android)

Hi, My application is getting about 10-20 crash reports a week (in the Android Dev console). I haven't reproduced the issue but here is the stack trace:

java.lang.NullPointerException
at android.app.AlertDialog.resolveDialogTheme(AlertDialog.java:142)
at android.app.AlertDialog$Builder.<init>(AlertDialog.java:359)
at ti.modules.titanium.ui.widget.TiUIDialog.createBuilder(TiUIDialog.java:278)
at ti.modules.titanium.ui.widget.TiUIDialog.<init>(TiUIDialog.java:56)
at ti.modules.titanium.ui.AlertDialogProxy.createView(AlertDialogProxy.java:54)
at org.appcelerator.titanium.proxy.TiViewProxy.handleGetView(TiViewProxy.java:410)
at org.appcelerator.titanium.proxy.TiViewProxy.getOrCreateView(TiViewProxy.java:396)
at ti.modules.titanium.ui.AlertDialogProxy$1.run(AlertDialogProxy.java:71)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4514)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)

The app was compiled with a late CI build of 2.1.x. I dont know the devices it is happening on (Google doesn't tell me) but based on user messages it appears to happen soon after launching the app. Any ideas?