There are two errors with audit handling in 1.6.x:
1) The change to use a hibernate interceptor (AuditableInterceptor) to handle date changed/changed by was backported from trunk, but setting the date changed/changed by in AuditableSaveHandler was NOT remove... so right now date changed/changed by is being set in two places in 1.6.x.
2) The functionality added to "chain" hibernate interceptors (also backported from trunk) does not work in 1.6.x. The net effect of this is that if you install the
Sync Module (which defines it's own hibernate interceptor) the AuditableInterceptor no longer functions.
(Note that, practically, bug #2 doesn't stop date changed/changed by from being recorded due to bug #1)