Trouble with a WinPE boot disk created by Symantec GBW on HP Elitebook 8440p

Hi, I'm having trouble getting a boot session to work on an HP elitebook 8440p and HP dc7900.

The boot disk is a standard boot disk created using Symantec GBW and works on a HP xw8600 workstation. It doesnot work on the laptop.

I initially thought it had something to do with SEE encryption, so I decrypt the HDD on the laptop, but no joy.

Symantec GhostCast Server version: 11.5.1.2266

Ghost Boot Disk: Standard Ghost Boot Disk

Performed a Multicast Ghostcast session - gave it the server IP address and it just hangs (message saying "Attempting to contact session <xxx>..."

Any idea what is wrong?