When changes are made to a record, as part of our auditing process, the Date Changed value on the record gets updated with both the date of the change and the specific time of the change. In this case only when merging and marking source constituents inactive the user finds that only the date is added to this value and the specific time is not. The user instead sees the general 00.00.0000 time entry entered.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.