Hi Iron,
Sorry for the late reply, haven't checked this forum for a while as I sent that phone back to be swapped out.
Prior to sending it back I checked all our internal network settings. It seems that the people who installed the system didn't setup DHCP as per Mitel instructions using DHCP option 43 or 125. Whenever the phone would boot it would use option 128+, then the error would occur. I set up the DHCP setting on our windows server 2008 as per information found on the internet and stopped the error reoccurring, however now The phone hangs at DHCP: discover, any other phone on our system works fine with the new settings.
Upon receiving the replacement I have exactly the same fault as before which means there is an issue within our system.
I am starting to think that the issue is due to the new phone has a much newer firmware then our 3300 / other phones. The new phone is running main 05.02.01.07 and boot 05.01.00.17, whereas our old units are running main 04.01.00.22 and boot 04.01.00.22. I would've thought that the firmware was backwards compatible!
I don't know where to go from now, I haven't found a solution to roll back the firmware to a previous version. Maybe I'll have to take the phone to our Mitel installer and get them to change the firmware / rectify the fault.
It is quite strange as I have changed multiple settings withing the network and other phones work fine, but these two phones with that particular firmware refuse to!
Thanks for your help!
Thanks,
Matt