If I skip the files which it complains about then the install proceeds ok. I'm not sure what I'm ending up with is properly patched though as the Windows Update site still offers the rollup to the client machine. WSUS also wants to reinstall some of the patches whil MBSA seems to think the machine is OK. I'm going back to individual patch integration as this rollup looks a mess. My guess is it's not modifying dosnet.inf properly when it's been integrated.