Yes you're right ejn63 (unless of course TPM needs to be virtualized...but that's another thing).
I'm not convinced its the OS I still think it's a BIOS issue.
EDIT :I've thought of something else. Under Security there is something called CPU XD...this should be disabled. It's enabled by default and needed for Hyper-V but prevents 64bit guests working in VMware. Again a shut down is needed. not a reboot.
So to recap
Virtualization - enabled
VT for Direct I/O - enabled
Trusted Execution - enabled
CPU XD - disabled