From OU Bugzilla Bug 1351. At present, with limited use of unit tests no problems have been found, but it's best to copy fixes and enhancements (from OU local cvs) to lib/simpletestlib.php functions now:
load_test_table - parameters.
wipe_sequences - global.
Note, simpletestlib.php now contains functions/classes from OU _tools/runsimpletest/dbutils.php, expectations.php ... and others.