Comment 23 for bug 386272

Same problem here. It was perfectly working in previous Ubuntu releases. Problem started after Karmic.
I can not even boot up machine without setting "acpi=off" in grub configuration

Short Info:
Hardware:
Toshiba X200-15K

uname -a
Linux pulsar 2.6.31-17-generic #54-Ubuntu SMP Thu Dec 10 17:01:44 UTC 2009 x86_64 GNU/Linux

BIOS Information
 Vendor: TOSHIBA
 Version: V2.50
 Release Date: 06/11/2008
 Address: 0xE5650
 Runtime Size: 108976 bytes
 ROM Size: 64 kB
 Characteristics:
  ISA is supported
  PCI is supported
  PC Card (PCMCIA) is supported
  PNP is supported
  BIOS is upgradeable
  BIOS shadowing is allowed
  ESCD support is available
  Boot from CD is supported
  ACPI is supported
  USB legacy is supported
  AGP is supported
  BIOS boot specification is supported
  Targeted content distribution is supported
 BIOS Revision: 2.80
 Firmware Revision: 2.80