In Element manager go to:
Configuration->Telephony->Global Settings->System Speed Dial
If your carrier sends call display with 10 digits you should set the CLID match length to the maximum size.
In your listing of speed dial entries you will find one of your speed dial settings is matching with the phone numbers and the name on that entry is what the BCM is replacing the inbound call display from the carrier with.
Next check the user speed dial on the prime set to see if there are some personal speed dial entries on your phone. I'm not sure if personal entries will also overwrite the name display because we barely ever use them but it's possible.
Under Configuration->Telephony->Sets->Active Sets. Pick the main phone, go to the tab Capabilities and Preferences and then on the bottom choose the tab User Speed Dial to check for any entries.
If it's a target line pointing to a different set then check those sets for their user speed dials too.
I can pretty much guarantee it's a speed dial entry somewhere.
If you want to check if you have any LAN-CTE sessions running that you do not know about you can go to:
Configuration->Applications->Lan CTE
The registered clients section of the screen will show any external machines that are logged in with the CTE client.
The number of active CTE desktops will give you a count on the number of sessions running.
If it's 0 with no registered clients then you do not have some mysterious external system doing things to the BCM and it's pretty much guaranteed to be a system speed dial entry causing the name to show up differently.
If you want to trace what the phone company is sending you then the BCM Monitor can be used (Well with a digital line it can, not sure about analog)
Figure out the bus number of your digital trunk module. (eg bus 4)
Administration->General->Hardware inventory
Our DTM-PRI module is on Main MBM 4
So go into BCM Monitor
Choose UIP tab
Choose Bus 40. (First number is the module, second number seems to be the port on the module which for our PRI there is only 1 port and the numbering starts at 0. If you had a BRI with 4 ports you would likely be 40, 41, 42, 43)
Pick PRI and a 15 minute timer will start for monitoring the signalling messages on that port.
You can see in the call setup message the name the carrier is sending along with the call display digits and DNIS digits.
So if the carrier is modifying the name you would see the data they are sending here.
The line monitor screen will show you the data with the modifications that your system speed dial entry has made. So in my case my mobile phone provider does not send any names, just the digits of the number. So looking at the trace I can see there is no name attached to the setup message but looking at the line monitor I see that the system put my name in because the mobile phone is in the system speed dial list and the number of the speed dial matches so it's the name shown on the call.