iscsi boot 2008 r2 failed

[chk]

I have been trying to sanboot some virtual machines lately.
1.install to a default workstation 9 virtual machine
2.install boot initiator(2003),install boot initiator and sanbootconf(xp),disable the LWF binding from regedit as suggested in http://blog.zorinaq.com/?e=41 (2008 r2),
3.use the VMDK i get from step 2 to create a iscsitarget
4.remove the disk from the virtual machines
5.boot with ipxe with command like:
dhcp
set keep-san 1
set initiator-iqn iqn.pxetest
sanboot iscsi:192.168.0.124::::iqn.2013-04.124:disk1


by doing this I get 2003 and xp boot just fine,however when it comes to 2008 I just keep getting bluescreen 7B and reboot.Can anybody tell me
what is causing it and how to make it work,Thanks.