SFC /scannow Cannot Repair Catsrvut.dll

I have Win7x64Ulti -Dell OEM I auto installed Sp1 in a moment of weakness (gave in to the pain of Windows 7).I have problems with some programs around com+ and VSS, notably Casper, but others as well so I ran sfc /scannow.Only one file shows up as a problem and Win says "cannot repair - source file corrupt". It is the windowssystem32catsvrut.dll, a com+ library.

Message follows:Cannot repair member file [l:24{12}]"catsrvut.dll" of Microsoft-Windows-COM-ComPlus-Runtime-QFE-CATSRVUT-COMSVCS, Version = 6.1.7600.16385, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch The attempted source is the winsxs folder.The 7600 would be pre SP1 if I read that right, so of course it cannot repair.So - I check the last disk image I had of this disk and in fact that file size and dttm is the same in the indicated winsxs folder but different in system32. I get that system32 is a secure dir/file and I cannot just copy/paste. But how to fix this is stumping me.

Weird part - I'm having trouble finding the actual file because of how Windows 7 uses Winsxs to dynamically link these files to the OS depending upon 32 or 64 bit access. I'm guessing there is a junction or symbolic link involved, because in Win explorer the file is correct size and date, in DOS it is correct size and date but when I run superfinder it shows all files with this name and system32 has wrong size and date.So it appears system32catsrvut.dll has a problem, and it further appears that the source to repair is from a pre-SP1 image in this library.I can't repair (OEM to SP1).I can't seem to copy the dll from the backup image.How do I get a valid copy of the dll? Or even tell if it is invalid?