we are running 2 w2k DHCP servers with all the scopes split over the 2 servers for resilience. we are also using layer 3 switches to seperate out the vlans into seperate subnets with a dhcp helper running on the switches to allow all sites to get their addresses from the same 2 servers. The problem is with the dhcp offers from the servers. These are the steps I would expect
data vlan = 89.0.0.0
voice vlan = 10.0.0.0
phone - dhcp discovery
server - dhcp offer (89.0.0.0 server1)
server - dhcp offer (89.0.0.0 server2)
phone - dhcp request(89.0.0.0 server1)
server - DHCP ACK
phone - DHCP release (phone will then switch to voice vlan and restart process)
what is happening is this
phone - dhcp discovery
server - dhcp offer (10.0.0.0 server1)
server - dhcp offer (89.0.0.0 server2)
phone - dhcp request(10.0.0.0 server2)
server - DHCP NACK

this is happening on both vlans and both servers. depending on which offer the phone picks up decides whether the phone will boot

any help would be greatly appreciated been working on this for a fortnight

Have you seen Mitel's document on setting up vlan's? We have had several customers do this and we just sent them the doc, they put it in and it worked. The only difference is they were not splitting up their dhcp servers. If you don't have the TSB's I can send them to you

Simon