undionly.kpxe and windows7 load problem

First of all thank this fantastic project. I have a problem when undionly.kpxe use to boot windows7 home (linux debian work fine). This screen is locked and the computer reset.
if I use the iso http://boot.ipxe.org/ipxe.iso works perfectly. Start ipxe.krn, dhcp send http://iscsi.informaticaamado.lan/boot.ipxe, load boot.ipxe.cfg, menu.ipxe and boot iscsi.
I've noticed that when I'm using RTL8169 ipxe.krn charge and otherwise undionly driver
What I'm doing wrong?
Thanks and regards.