FlexTable broken for simple 5 row / 2 column table
===

It appears that something changed just tonight, and now FlexTable is broken in such a way that it is impossible to create a table such as below with just 5 rows and 2 columns:

    var ROWS=5;
    var COLS=2;

    function doGet() {
      var app = UiApp.createApplication();
      var grid = app.createFlexTable().setBorderWidth(1);
      app.add(grid);
      
      
      for (var row=0; row<ROWS; row++)
        for (var col=0; col<COLS; col++)
          grid.setText(row, col, "cell-"+row+","+col);
          
      return app;
    }

It gets as far as cell-2,0, but then gets "Error encountered: An unexpected error occurred".

This was working correctly just a few hours ago - but now my web-app which makes extensive use of FlexTable is completely broken.

Any ideas?

Josh