kmarsden123,
You are correct about it being a 5000, but for future reference a 5320 IP Phone can be used on either the 3300 or the 5000. There are two key indicators that this is on a Mitel 5000
1. It is using pretty much the default keymap
2. It has Call Keys
I am not sure why that even have an IC Key though as far as I can tell it isn't needed, but that is not the issue here. Have the unplug their phone so it powers down and then plug it back in.
If the problem persists after that then we may need to look at what the system thinks is going on.
Thanks,
TE