[FIXED] Testing disabled - FileFieldValidateTestCase

We have been getting results on multiple instances of a consistent single failure (and 7 exceptions) in Drupal HEAD's FileFieldValidateTestCase. Until it can be resolved, automated testing has been disabled. Please help us investigate why, how, and in what conditions this test is failing.

Update: Thanks to Damien (DamZ) the issues should now be resolved and testing has been re-enabled.