Vista Security Centre is broken!

Hi,
I've had problems with the Security Centre nearly since I've had Vista, and I have tried to fix it once before, without success. But now with SP1 available I want to either fix it or face a total re-install. Several security updates have failed before due to these issues, so I don't hold out much hope of SP1 being a knight in shining armour and fixing everything.

It started with Vista freezing up during a reboot after installation of a ViewSonic monitor driver, and after that the Security Centre suddenly didn't recognising my anti-virus program (AVG). It's an issue like the one posted here. And like that post explains a few ways to fix the issue, I did the same. But the trouble is, it didn't work for me. I turned off Windows Management Instrumentation as in Method A, and instead of deleting, I renamed my Repository folder. But upon rebooting, it didn't create the folder again, and it didn't fix the underlying issues. Microsoft in all their wisdom suggested a repair install, but after 2 hours that failed as well.

Here is an image of my Security Centre.

<<-- click to expand

At present my old repository folder is called old.repository.001 - this is the result of two attempts to get Windows to recreate it. I have trouble remembering exactly but I think I renamed it old. and another method renamed it .001 In any case, there is no other folder in system32/wbem/ called repository and all the files in the old.repository.001 seem to be as they were.

I'd really like some good advice here. I don't want to do a clean install of Vista, but I'm almost sure that SP1 is not going to succeed while my Security centre is in such a state. I have scanned the system for viruses and it appears to be clean. I'm just not sure how to properly go about fixing the repository. The only other thing it seems to affect is setting system restore points. When Windows installs an update, it successfully creates a restore point, but if I try to do it manually it invariably fails and it gives me a "transient error" warning, suggesting that if I try again, it might work (which it doesn't).

So this is last stop before reinstall but I'm reluctant to do that, as it takes a lot of time and annoyance.

Thanks for your input. I appreciate it.