When you install the module, it breaks the 'view' array variables, which are also included in contemplate module.

Such as:

$node->field_fieldname(array)

    $node->field_fieldname[0] (array)

        $node->field_fieldname[0]['value'] **
          
        $node->field_fieldname[0]['view']

With cck fieldgroup tabs module:

$node->field_fieldname[0]['view'] 

does not exist.