Problems with android bluetooth permissions

First, sorry for my bad English, I'm Spanish (And new to android developing). I am developing a simple Bluetooth file sender, I am basing on BluetoothChat android example step by step.

Now I have a bluetooth activate request to the user, and select yes or no option application crashes.

I have the permissions declared in the Manifest.

The thing is, if user select yes to activate bluetooth, bluetooth actually activates but app still crashes after that.

I don't know if ACRA is in conflict with this, I'm using it because mi device is huawei u8650 and I don't find usb drivers to run app directly in the device from eclipse, so I move the .apk file every time to SD card.

Here is the manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.BTSender"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="10" />    
    <uses-permission android:name="android.permission.BLUETOOTH"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" android:name="MyApplication">
        <activity
            android:name=".BluetoothSenderActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

and here is the main ( and only ) activity:

package com.BTSender;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Intent;