I have a brand new TS200 which is running ESXi 4.1 from a USB key.
The problem I have with it is if I shut the system down (i.e. shutdown ESXi) it shuts down ok but when I power the server back on (from it's flashing green power LED state) it hangs with "uEFI Starting" on the screen and the yellow "!" LED illuminates.
Having looked at the event logs via IMM I can see this error:
"A software NMI has occurred on system "SN# xxxxxxx"
If i disconnect the power and reboot the system boots fine.