Sorry for being late to the party...
Try this if you have an old 100mbps switch laying around: Connect the mobo to your existing gigabit switch as you do now. Then put a 100mbps switch between the Prime and the gigabit switch.
The hope here is that the two switches can better interoperate than your Intel NIC and the Prime. This trick served me very well when I had interoperability issues between a DSL modem and a gigabit WAN port of a router.
Good luck.
Try this if you have an old 100mbps switch laying around: Connect the mobo to your existing gigabit switch as you do now. Then put a 100mbps switch between the Prime and the gigabit switch.
The hope here is that the two switches can better interoperate than your Intel NIC and the Prime. This trick served me very well when I had interoperability issues between a DSL modem and a gigabit WAN port of a router.
Good luck.

















