cannot re-assign $this in PHP5

[admin]

Fatal error: Cannot re-assign $this in c:\PHP\includes\authentication.inc.php on line 18

I am getting this error while trying to use an object originally written in PHP4.

The line causing the error is where the 'table' object is imported:

class CAuthentication extends CBase
{
var $table;

function CAuthentication( $tableName )
{
$this->table->tableName = trim( $tableName ); // this is the line that causes the fatal error
}
}

Does anyone know what this means or how to fix it?

Searching for others who've had the same problem hasn't revealed anything and I'm baffled.

voidstateWorks for me: is it something you left out of your post?