SV8100 Virtual extension question

[stormchops]

Hi,

I have an analogue (non nec) doorphone set up to ring a virtual extension. 8 phones have a virtual key for the extension. however, when it rings nothing is displayed on the handset to notify the extension of who is calling (i'd expect it to display the VE name or the name of the doorphone) have i missed a setting somewhere?

Thanks