I know this is so far out of date, but I had this same problem on ESXi 5.1 hosts while installing w2k8r2 and w2k8r2sp1 boxes. The issue was that I was enabling Hot-Add Memory in the configuration parameters. Once I unchecked that box while creating the VM, the 70+ Generic Bus problem went away.
- As for existing boxes, I've seen the Generic Bus' go away, and I've seen them persist. so I don't know the issue there. I have a ticket open with support, but they're acting as if they've never seen it before - let alone know what a root cause is.
/Sorry for dragging up old posts - but I thought it applied. I know others have seen the same issue.