I know this might not be a ton of help - but are the nics REALLY set to E1000 - or does the VCD gui show that (and if you look in vcenter they are really VXNET3)?
I ask because I have seen nics after instantiate show as E1000 in VCD, but they are really correct in vCenter. (A bug in 1.5 that I have not gotten around to testing in 5.1 yet)