In an ezxmltext.
If you have a link to an object without any main node (I don't know why),
You won't be able to display the ezxmltxt attribute, the page will crash.
In the apache log:
[Tue Aug 14 05:14:25 2007] [error] PHP Fatal error: Call to a member function on a non-object in /data2/premiere/prod/kernel/classes/datatypes/ezxmltext/handlers/output/ezxhtmlxmloutput.php on line 242

One test is not at the good place:
$node =& $object->attribute( 'main_node' );
$nodeID = $node->attribute( 'node_id' );
if ( $node )
{
$view = $element->getAttribute( 'view' );
should be
$node =& $object->attribute( 'main_node' );
if ( $node )
{
$nodeID = $node->attribute( 'node_id' );
$view = $element->getAttribute( 'view' );