"No bootable device - insert boot disk" after restart on Ubuntu 10.04 b1 update

I was making an update on my Ubuntu 10.04 beta1 64-bit PC when, after reboot I get

PXE-E61: Mediaa test failure, check
cable PXE-M0F: Exiting Intel Boot
Agent.

No bootable device - insert boot disk
and press any key

How did my boot record disappear ?

BIOS > Boot

Boot Menu Type : Normal
Boot Device Priority : 
                       
                       
                       
Hard Driver Order    : No Hard Disk Drive
CD/DVD ROM Drive Order : 
Removable Drive Order : No Removable Drive
Boot to Optical Devices : 
Boot to Removable Devices : 
Boot to Network : 
USB Boot : 

Answer

Tried all sorts of things - finally opened the chassis - for some odd reason the cable connecting to the hard-disk got burnt. The computer was on the whole night though, but that shouldnt be a reason. Shouldnt be a voltage issue as Im connected to a 1kVA Delta UPS which handles the voltage fluctuations (if any).