CLONE -Clearing validation result (via 'errorString') prevents new validations

Steps to reproduce:
1. Create the example 'Clearing a validation error' from http://livedocs.adobe.com/flex/3/html/help.html?content=validators_5.html or use attached file.
2. Run the example.
3. Press 'Submit', press 'Clear', press 'Submit', press 'Clear' etc...

Actual Results:
The validation error appears the first time the user clicks 'Submit'. After the first 'Clear', the validation error doesn't appears anymore.

Expected Results:
Validation error to appear every time if validation fails. Tested with SDK 3.3 and there it works as expected.

Workaround (if any):
Create a custom validator and set 'errorString' to display any validation error.