After correcting errors on a form and saving, click Validate to see if the data now passes validation.
Check the Status of the validation on the main My Tasks page or at the bottom of the form under Task Actions |Change Status To.
It should say Validated. If the validation cannot be completed for some reason, the status of that document will be Failed. Ask your TI administrator to check the Event Log for the reason.
For a list of all statuses, see List of Statuses.