Problem with disabled VT
Some recent ThinkPad models ship with Intel CPUs that implement the Intel VT extensions for hardware-supported virtualization, but the capability is disabled by the BIOS. There is no known solution. See this LKML thread.
BIOS Update for ThinkPad Z61e, Z61m, Z61p, Z61t
Lenovo solved the problem with a BIOS update on June 6, 2007. Flashing the new BIOS adds a configuration option to the BIOS to allow or disallow the use of VT.