I have CUCM 7.1 and CUPS 7.0.3
1. sometimes CUPC font is being changed automatically without any manual change from the users!!!
2. The integration between CUPC and the IP phone is lost if a user logs out from the IP phone Extension Mobility and then logs in again. To let the integration work again, the client must be restarted or disable the desk phone from the client and enable it again!!!
3. Sometimes IM messages are not received saying that Person did not receive your message because the message could not be sent, as per Cisco troubleshooting guide again later or use another method to contact this person (which is not accepted by customer)