i’m using ubuntu 12.04 and the most current fog. all clean installs. when i try to pxe boot i get the following

t04: access violation
E36: error received from TFTP server
MOF: exiting PXE boot

I have configure option 66 and 67 on my windows dhcp server and unclicked 60. i have also followed the steps that make all the passwords the same.

please help