Hi Dave and MitelPassion,
We have a couple of PCs that are still working. All PCs worked when the software was first installed. It was only after either a reboot of the PC or just exiting and restarting the software that it stopped working on most of the systems.
All PCs have all versions of the .Net Framework installed.
There is no router between the 3300 and the PCs. All are on the same subnet. All get their IPs from the same DHCP servers (phones and handsets).
We also since found that if we entered the IP address of the phone on a system that was not working the software worked fine. This is not viable long term as the phones seem to get a different IP address each time they start (DHCP issued by DHCP servers not the 3300 and we can't change that unfortunately).
There does not seem to be a pattern as we find that PCs with the same hardware, one can connect while the other cannot. PCs not working can have different hardware configurations (and network cards).
The PCs are not plugged into the handset PC network socket.
I have read the FAQ and nothing there seems to apply. I tried playing around with the network card settings of a PC that doesn't work (tried all the various flow control settings, full and half duplexing at various speeds).
As I can connect to the admin web interface of the 3300 from a PC which cannot use dn2ip I am guessing that port 80 isn't an issue.
I have verifed the 3300 settings and they are exactly as the IT guide says to set them (no access on the system policy except for the IP Telephones - all which is set to Read Only).
It's really got me scratching my head.
Thanks again for any suggestions you may have.