CUCM 9.1 system using 8945 phones. I built a custom phone service to facilitate Extension Mobility login. Because the system is AD/LDAP integrated, I created a menu that let's the user select their username from a list. So the service points to a static IP Phone Menu XML, which includes the list of EM-enabled usernames, and redirects to a IP Phone Input, which pre-fills the username and device name and only requires the PIN, which then redirects to the EM login URL. Usually this works just fine. However, sometimes, the IP Phone Input will not accept input from the keypad. The work around seems to be to pick up a line, use the keypad (any key), and hang up the line. Then the service accepts the keys. It only seems to happen maybe 1 out of 10 attempts. Any idea what's happening?