Fresh install of Moodle with PHP 5.3 results in the following error occuring when trying to run Unit Tests through Moodle:

Fatal error: Call to undefined method AutoGroupTest::GroupTest() in D:\xampp\htdocs\moodle\admin\report\unittest\ex_simple_test.php on line 31

Problem did not occur when I rolled back to PHP 5.2.9.

The problem was resolved in PHP 5.3 when i commented out this line in /admin/report/unittest/ex_simple_test.php (line 31)

$this->GroupTest($test_name);