R730 Broadcom BCM5720 won't PXE

Hi,

I've got some R730 with some onboard Broadcom BCM5720 (4x1Gbps) that really don't like to PXE. On the DHCP server I can see the various requests and responses, but on the server itself it'll just hang, so I'll get something like:

CLIENT MAC ADDR: XX XX XX XX XX XX GUID: .....
DHCP..\

And at that point the spinning cursor will stop.

I've made sure that NIC1 is set to PXE and updated the all firmware. Whereas before after a few reboots it would eventually give in and work, I'm having no joy today.

Annoyingly I have some other R730 with onboard Intel and some R720 with what I presume to be pretty much the same onboard Broadcom and they both work fine!

Any ideas anyone?

Cheers,

Jamie