In November a user requested a new Mac for publishing purposes; after a long wait we finally got it last month. In addition to her 27" iMac, I was given a new 13" MBP since I'm familiar with OS X and we need someone to support her. Both Macs are running OS X 10.8.2. After getting them, I naturally bound them to our domain using Directory Utility, which seemed to work like a charm. We could access network shares, network users can log in to them, Domain Admins have admin access on them, printers work, intranet works, etc. However, it turns out that each of these Macs are generating 43,000 plus errors on the Domain Controllers every week. We have a mixed 2003/R2/2008/R2 environment, with both DCs being 2008 R2. I'm really unsure of how these errors keep being generated, since both machines are functioning just fine; but my security admin is going nuts about them. Attached is a screenshot of the error, which is Windows ID 4776.