title: App is close when back button in on phone but no in another
body: <p>I have an app that goes to the homeScreen when I click the back button in certain activity using a Galaxy SII (Android 4.0.4) but it does goes back normally to all the previous activities that not call the finish() method when using an HTC EVO (Android 2.3.5). </p>
  
  <p>I was thinking it was an android version feature and now I am more secure it is. I tried using the emulator in those version and the result was the same. It's an android version problem.</p>
  
  <p>Here I attach the images, so it could be clear what's the problem.</p>
  
  <p><img src="https://i.stack.imgur.com/HylkF.png" alt="Main Screen">
  <img src="https://i.stack.imgur.com/z5mFQ.png" alt="Second Activity">
  <img src="https://i.stack.imgur.com/u7uSu.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/xlTAy.png" alt="enter image description here"></p>
  
  <p>If I click the back button at this position, it takes me out of the app to the home screen.
  That is with the Galaxy S3</p>
  
  <p>But with the android 2.3.5, this is how it works.</p>
  
  <p><img src="https://i.stack.imgur.com/CIsF6.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/xez64.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/RCuhD.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/cSsIy.png" alt="enter image description here"></p>
  
  <p>In the 2.3.5 version, I click back, an every activity is back at the foreground.
  Any clue about that problem?</p>
  
  <p>The code of the manifest:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.silm.sfa"
  android:versionCode="2"
  android:versionName="1.1" &gt;
  
  &lt;uses-sdk
      android:minSdkVersion="8"
      android:targetSdkVersion="17" /&gt;
  
  &lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /&gt;
  &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
  &lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /&gt;
  
  &lt;application
      android:name="com.silm.sfa.app.App"
      android:allowBackup="true"
      android:icon="@drawable/sfa_new_version_logo"
      android:label="@string/app_name"
      android:theme="@android:style/Theme.NoTitleBar" &gt;
      &lt;activity
          android:name=".Splash"
          android:screenOrientation="portrait" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".Login"
          android:label="@string/app_name"
          android:screenOrientation="portrait"
          android:theme="@android:style/Theme.NoTitleBar" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".Prefs"
          android:label="@string/config"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".Summary"
          android:label="@string/resumen"
          android:theme="@android:style/Theme.Dialog" 
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name="com.jvra.signature.SignatureActivity"
          android:configChanges="orientation"
          android:theme="@android:style/Theme.Dialog"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".System"
          android:theme="@android:style/Theme.NoTitleBar"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".find.Finder"
          android:configChanges="orientation"
          android:theme="@android:style/Theme.NoTitleBar"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".Dashboard"
          android:theme="@android:style/Theme.NoTitleBar"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".Help"
          android:label="@string/help"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".bprocess.OrdersRecipe"
          android:label="@string/help"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".bprocess.DebitNotesProcess"
          android:label="@string/help"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".bprocess.CreditNotesProcess"
          android:label="@string/help"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".bprocess.StatementProcess"
          android:label="@string/help"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".bprocess.Products"
          android:label="@string/help"
          android:screenOrientation="portrait" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".signature.SignatureActivity"
          android:label="@string/help"
          android:screenOrientation="landscape" &gt;
      &lt;/activity&gt;
  &lt;/application&gt;
  
  &lt;/manifest&gt;
  </code></pre>
  
  <p>Code of the back button method:</p>
  
  <pre><code>@Override
  public boolean onKeyDown(int keyCode, KeyEvent event)
  {
  
      if( event.getAction() == KeyEvent.ACTION_DOWN )
          if( keyCode == KeyEvent.KEYCODE_BACK )
          {
              DetailFragment detail = (DetailFragment) getSupportFragmentManager().findFragmentByTag(FIND_DETAIL_FRAGMENT);
              if( detail != null &amp;&amp; detail.isVisible() )
                  searchBar.setEnabledSearchButton(true);
          }
      return super.onKeyDown(keyCode, event);
  }
  </code></pre>