App crash

I have one flex mobile application.
It works fine on Android without "word prediction activated" and also with "word prediction activated" an a device with 240 DPI however my application is designed to work on a 120 DPI device and with word prediction activated and on this scenario, the app crash while typing text on a TextInput.

Steps to reproduce:
1. Type Luiz153
2. Remove "z" to get Lui153
3. Type "o" in the old "z" place to get Luio153

At this moment the app just crash with the following android stack trace log:
java.lang.StringIndexOutOfBoundsException: length=5; regionStart=-2; regionLength=7
at java.lang.String.startEndAndLength(String.java:588)
at java.lang.String.substring(String.java:1475)
at java.lang.String.subSequence(String.java:1862)
at com.adobe.air.AndroidInputConnection.setComposingRegion(AndroidInputConnection.java:183)
at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:342)
at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:77)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)

Aditional info: If I change the TextInput skin class from spark.skins.mobile.TextInputSkin to standard desktop TextInputSkin, this issue don't occurs but of course I will get a lot of issues because it's not optimized for mobile so I believe that this issue is related with the flex mobile TextInputSkin).