DMZ 1.7.1 (DataMapper OverZealous Edition)

[eluser]OverZealous[/eluser]
@j0nxiest

You aren't using it right. The transaction hasn't failed, the validation has. You need to check the result of the $user->save() call to see if the validation failed. The validation result is also stored in $object->valid.

Transactions are only used to group a series of queries, just like in normal SQL.