Same here, kubuntu 14.04 64bits on a Dell Precision 390 with nVidia Quadro. No wireless cards.
Tried with nouveau nvidia driver and the 313 proprietary driver.
Had BIOS version 2.4.0, upgraded to 2.6.0 (thought I had bricked the mobo in the process, as kubuntu did not shutdown as part of the bios upgrade process, so I had to long-press the power button, then the pc wouldn't boot anymore - beep codes, fixed with a BIOS reset, then used a usb live debian wheezy rescue to do the BIOS upgrade).
When Booted with a usb pendrive with debian wheezy rescue, it powers off.
I have 3 other Precision 390 machines with debian wheezy, and they shutdown correctly.
Same here, kubuntu 14.04 64bits on a Dell Precision 390 with nVidia Quadro. No wireless cards.
Tried with nouveau nvidia driver and the 313 proprietary driver.
Had BIOS version 2.4.0, upgraded to 2.6.0 (thought I had bricked the mobo in the process, as kubuntu did not shutdown as part of the bios upgrade process, so I had to long-press the power button, then the pc wouldn't boot anymore - beep codes, fixed with a BIOS reset, then used a usb live debian wheezy rescue to do the BIOS upgrade).
When Booted with a usb pendrive with debian wheezy rescue, it powers off.
I have 3 other Precision 390 machines with debian wheezy, and they shutdown correctly.