Android Mudando Tema da Aplicação

Estou recebendo a seguinte exception ao tentar executar minha aplicação android:

E/AndroidRuntime(15147): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.ideall.zapzap/br.com.ideall.zapzap.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.

Porém já alterei em todos os arquivos possíveis para o tema que se pede:

styles.xml (values)

<resources>

    <!--
        Base application theme for API 14+. This theme completely replaces
        AppBaseTheme from BOTH res/values/styles.xml and
        res/values-v11/styles.xml on API 14+ devices.
    -->
    <style name="Theme.AppCompat" parent="Theme.AppCompat">
        <!-- API 14 theme customizations can go here. -->
    </style>

</resources>

styles.xml (values-v11)

<resources>

    <!--
        Base application theme for API 11+. This theme completely replaces
        AppBaseTheme from res/values/styles.xml on API 11+ devices.
    -->
    <style name="Theme.AppCompat" parent="Theme.AppCompat">
        <!-- API 11 theme customizations can go here. -->
    </style>

</resources>

styles.xml (values-v14)

<resources xmlns:android="http://schemas.android.com/apk/res/android">

    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="Theme.AppCompat" parent="Theme.AppCompat">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>

</resources>

AndroidManifest.xml

 <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.AppCompat" >

        ...

        <activity
            android:name="br.com.ideall.zapzap.MainActivity"
            android:label="@string/app_name" 
            android:theme="@style/Theme.AppCompat">

O erro continua! Faltou alterar em algum lugar?