title: showDialog in Activity not displaying dialog
body: <p>Here is my code:</p>
  
  <pre><code>public class TasksList extends ListActivity {
      ...
      private static final int COLUMNS_DIALOG = 7;
      private static final int ORDER_DIALOG = 8;
      private Bundle bundle = new Bundle();
      ...
       /**
       * @see android.app.Activity#onCreateDialog(int)
       */
      @Override
      protected Dialog onCreateDialog(int id) {
          Dialog dialog;
          final String[] columns;
          Cursor c = managedQuery(Tasks.CONTENT_URI, null, null, null, null);
          columns = c.getColumnNames();
          final String[] order = { "Ascending", "Descending" };
  
          switch (id) {
          case COLUMNS_DIALOG:
              AlertDialog.Builder columnDialog = new AlertDialog.Builder(this);
              columnDialog.setSingleChoiceItems(columns, -1, new DialogInterface.OnClickListener() {
                  @Override
                  public void onClick(DialogInterface dialog, int which) {
                      bundle.putString("column", columns[which]);
                  }
              });
              dialog = columnDialog.create();
              break;
          case ORDER_DIALOG:
              AlertDialog.Builder orderDialog = new AlertDialog.Builder(this);
              orderDialog.setSingleChoiceItems(order, -1, new DialogInterface.OnClickListener() {
                  @Override
                  public void onClick(DialogInterface dialog, int which) {
                      String orderS;
                      if (order[which].equalsIgnoreCase("Ascending"))
                          orderS = "ASC";
                       else
                          orderS = "DESC";
  
                      bundle.putString("order", orderS);
                  }
              });
               dialog = orderDialog.create();
               break;
          default:
              dialog = null;
              break;
          }
  
          return dialog;
      }
      /**
       * @see android.app.Activity#onOptionsItemSelected(android.view.MenuItem)
       */
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          switch (item.getItemId()) {
          case SORT_MENU:
              showDialog(COLUMNS_DIALOG);
              showDialog(ORDER_DIALOG);
              String orderBy = bundle.getString("column") + bundle.getString("order");
  
              Cursor tasks = managedQuery(Tasks.CONTENT_URI, projection, null, null, orderBy);
              adapter = new TasksAdapter(this, tasks);
              getListView().setAdapter(adapter);
  
              break;
          case FILTER_MENU:
              break;
          }
          return false;
      }
  }
  </code></pre>
  
  <p>The <code>showDialog</code> doesn't display the dialog. I used the Debugger and it does executes these statements, but the dialog doesn't show.</p>