Vista Bus. x64 SP2 install issues

Greetings,

I've been trying off and on to install SP2 on my Vista Business x64 SP1 box since it was published. I've managed to generate two different error codes (80070002 and, though only once, 8007000D) through attempting the various "fixes" listed in MS's KB.

I've run the system update readiness tool (didn't find anything wrong), I've uninstalled disk imaging and anti-virus software, stopped the service, deleted temp files and restarted it, I've done everything of which I can think short of a re-installation (which is looming).

Just wondering if anyone had run in to similar problems -- I get the same error code with both Win Update (dies at 18% every time) and a local installation. It's great that it tells me a file's not found, wouldn't it be wonderful if it actually told me which file was missing?

Thanks in advance!