multiple leases on dualboot clients

Hello folks,

All u people using isc dhcp server.
I have a problem with clients getting 2 leases due to the client
identifier thing.....

Is there a solution that does not involve rewriting the source code to
the ISC server?
The unique client identifier sent by XP can not be ignored by using any
options in the dhcpd.conf file, i have realized that after some
research. It is not supported because it is a violation of the rfc.
My conclusion is unless i write some code to fix this i will have to
make gigantic host declarations in my config file or manipulate the
client id sent by my xp clients so that it does not send any value to
the dhcp server (if possible)
The environment is dualboot pxe clients, (Novell Zenworks 7). ISC
3.05rc3
Are my conclusions correct, or is there a smarter solution to this
problem? Using microsoft dhcp is not an option right now..... :-)