No static enties on any DNS server. At least nothing that is jumping out saying it is static. All DNS servers have the same or at least similar entries. The difference are the local machine IP addresses.
Could this error be caused by a timing issue? I found the time on DC1 behind by 3-4 minutes of DC3. I changed the time on DC1 to see if there and change will occur.
Regarding the mystirous software: there is no executable matching the entry. The outsourcing company says its not one of there's and they don't know what it is. All I know is that it was installed at their shop, with or without their knowledge.