Got some strangeness...
A while back I did an in-place upgrade and everything seemed to go ok - people are using 2010 with no problems.
Today I went to mysite and tried to create a new site below it (FAST search) and just get the dreaded error occured.
I looked at the logs (ULS viewer) and see a critical error saying duplicated data - so I googled and came up with a post saying that upgrades can often still reference the 12 hive and to rename the folder to .old
So I did... now I get a bunch of critical errors in the log (although SP still seems to work fine) saying that c:/...../12 is an invalid path.
Why are things still looking at 12 and not 14?
How can I see what is referencing it?