From debugging, I can see that if any lazy property is uninitialized, Hibernate assumes that all lazy properties are uninitialized, so no updates are necessary. Now that there are "lazy groups", this assumption is not correct.

Static update strings appear to cover only the following situations:
1) there are no uninitialized properties (so all singular attributes should be updated);
2) lazy properties are uninititalized (so only non-lazy, singular attributes should be updated).

In addition to non-lazy properties, all singular properties included in initialized "lazy groups" should be updated.

A related bug is that calling a setter on a lazy property only initializes that one lazy property. It should also initialize other properties in the same lazy group.