I have a CallManager 22.214.171.12400-2 installation where the Caller Display of the Calling Party is NOT displayed until the destination goes off hook - This is between two internal handsets connected to the same cluster.
The user receiving the call only see's the DN displayed on the screen before they pick up the handset, once they do, they see the Caller Display configured on the Calling handset.
They have the problem through the installation, but these results are taken from 2 x 7970 handsets.
Apparently, they used to see the CLID of the calling phone before but I can not confirm this.
Unfortunately I do not have a lab of this level to carry out any testing, so any help is appreciated.