I met the same problem. I use Gigabytes G33-DS3R motherboard with built-in NIC Realtek 8111B. I can boot to syslinux boot menu(using vasemenu.v32) via PXE boot(pxelinux.0). However, when I choose any item of the menu, the system is halt. Also, I test with same process on DELL Oplex 755, it could boot to any item without error.