Problem beim einbinden von einem GridLayout in ein Tab VIew

package info.app;


import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.TabHost;


public class Info_ApplikationActivity extends TabActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);


        Resources res = getResources(); // Resource object to get Drawables
        TabHost tabHost = getTabHost();  // The activity TabHost
        TabHost.TabSpec spec;  // Resusable TabSpec for each tab
        Intent intent;  // Reusable Intent for each tab


        // Create an Intent to launch an Activity for the tab (to be reused)
        intent = new Intent().setClass(this, Standortinformation_activity.class);
        spec = tabHost.newTabSpec("Standort").setIndicator("Standort",
                          res.getDrawable(R.drawable.ic_tab_standort))
                      .setContent(intent);
        tabHost.addTab(spec);
        
        intent = new Intent().setClass(this, Fachbereiche_activity.class);


        // Initialize a TabSpec for each tab and add it to the TabHost
        spec = tabHost.newTabSpec("Fachbereiche").setIndicator("Fachbereiche",
                          res.getDrawable(R.drawable.ic_tab_fachbereich))
                      .setContent(intent);
        tabHost.addTab(spec);


        // Do the same for the other tabs
        intent = new Intent().setClass(this, Links_activity.class);
        spec = tabHost.newTabSpec("Links").setIndicator("Links",
                          res.getDrawable(R.drawable.ic_tab_link))
                      .setContent(intent);
        tabHost.addTab(spec);
        
        
        intent = new Intent().setClass(this, GalleryActivity.class);
        spec = tabHost.newTabSpec("Fotos FH").setIndicator("Fotos FH",
                          res.getDrawable(R.drawable.ic_tab_gallery))
                      .setContent(intent);
        tabHost.addTab(spec);
        
        tabHost.setCurrentTab(0);
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
    	switch(keyCode)
    	{
    		case KeyEvent.KEYCODE_BACK:
    			// was hier halt passieren soll
    			return true;
    		default:
    			return super.onKeyDown(keyCode, event);
    	}
    }
}

package info.app;


import android.app.Activity;
import android.os.Bundle;
import android.widget.GridView;


public class GalleryActivity extends Activity {
	public void onCreate(Bundle savedInstanceState) { 
		super.onCreate(savedInstanceState); setContentView(R.layout.fotos); 
		GridView gridview = (GridView) findViewById(R.id.gridview); 
		gridview.setAdapter(new ImageAdapter(this)); }
}

package info.app;


import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;


public class ImageAdapter extends BaseAdapter {
    private Context mContext;


    public ImageAdapter(Context c) {
        // TODO Auto-generated constructor stub
        mContext= c;
    }


    public int getCount() {
        // TODO Auto-generated method stub
        return mThumbIds.length;


    }


    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return null;
    }


    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }


    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        ImageView imageView;
        if (convertView == null) {  // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);            


            imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8, 8, 8, 8);


            //myButton.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT, Gravity.CENTER_HORIZONTAL));






        } else {
            imageView = (ImageView) convertView;
        }


        imageView.setImageResource(mThumbIds[position]);
        return imageView;


    }


    // references to our images
    private Integer[] mThumbIds = {
            R.drawable.pic1
    };
}

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:padding="5dp"
        android:background="@drawable/background1">
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"/>
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:padding="5dp"  >
            <TableLayout android:id="@+id/tableLayout1" android:layout_width="match_parent" android:layout_height="match_parent">
                <TableRow android:id="@+id/tableRow1" android:layout_width="wrap_content" android:layout_height="wrap_content">
                </TableRow>
                <TableRow android:id="@+id/tableRow2" android:layout_width="wrap_content" android:layout_height="wrap_content">
                </TableRow>
                <TableRow android:id="@+id/tableRow3" android:layout_width="wrap_content" android:layout_height="wrap_content"></TableRow>
                <TableRow android:id="@+id/tableRow4" android:layout_width="wrap_content" android:layout_height="wrap_content"></TableRow>
            </TableLayout>
        	
        </FrameLayout>
    </LinearLayout>
</TabHost>

<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/gridview"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:columnWidth="90dp"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
/>