Apple has released an update tonight complementary 10.7.3 OS X Lion, with the intention to fix a bug related to generating backups Time Machine:
This update fixes a problem with restoring a Mac from a backup of Time Machine. We recommend you install this update to all users using the system with 10.7.3 backups Time Machine.
The update is delta, and occupies a measly 38 Kb, a simple patch seems minor, but the fact that Apple has been baptized as a complementary upgrade from version 10.7.3 may indicate that a patch is important. We recommend upgrading everyone, but especially if you make regular copies of Time Machine and you planning to migrate or restore to a clean installation of the system. As always, the update is on the official website of Apple or the updates panel system OS X.