Vegas on Vista

I have a machine I upgraded to Vista Business from XP Pro. I have all the
latest updates.

I have the latest version of Sony Vegas Pro 8, which is Vista compatible,
but it will not install correctly. The event viewer gives the following
error for each plugin it tries to install:

Activation context generation failed for "C:\Program Files\Sony\Shared
Plug-Ins\Audio\xpvinyl.dll". Dependent Assembly
Microsoft.VC80.CRT,processorArchitecture="x86",pub licKeyToken="1fc8b3b9a1e18e3b",type="win32",versio n="8.0.50727.762"
could not be found. Please use sxstrace.exe for detailed diagnosis.

It seems to be a problem related to getting the C runtime. I have looked in
the Winsxs folder and that version appears to be there. I have downloaded
and installed vcredist.exe and tried about everything else I know of. Other
programs install fine. And Vegas installed fine on XP.

Any suggestions as to what I might do?

Thanks.