Android Holotheme with modal Windows making trouble

Hey,

i try to assign a holo-theme to my android Application- that worked. But if i declared a window as modal=true it doesn't work anymore ...

I've read another post regarding this problem, but i can't figure out the whole solution...

I am using this Code inside my tiapp.xml

<android xmlns:android="http://schemas.android.com/apk/res/android">
        <tool-api-level>14</tool-api-level>
        <manifest>
            <uses-sdk targetSdkVersion="14"/>
            <application android:theme="@android:style/Theme.Holo">
 
                <activity android:name=".ThemetestActivity" android:theme="@android:style/Theme.Holo">
                    <intent-filter>
                        <action android:name="android.intent.action.MAIN"/>
                        <category android:name="android.intent.category.LAUNCHER"/>
                    </intent-filter>
                </activity>
 
                <activity android:name="org.appcelerator.titanium.TiModalActivity" 
       android:theme="@android:style/Theme.Holo" />
 
            </application>
        </manifest>
    </android>

What am i doing wrong?