This applies to some versions of the Messaging (CallPilot) 100/150 software with the Call Center option: Before restarting the unit you must first go into the ICS and remove the feature codes the Call Center uses.
To do this enter **XFTEST followed by the usual installer password. Page through the feature codes with the softkeys and deactivate each Call Center feature code (do NOT delete the voice mail feature codes!). The ICS and CallPilot will re-negotiate the Call Center feature codes automatically as part of the CallPilot's startup process.
If you don't do this, the feature codes for Agent Login/Out, Supervisor, Ready/NotReady, etc. will all change from the usual F901, F902, etc. to F907, F908, and so on. If you've programmed buttons with those features onto buttons, they will break, of course. And the only way to fix it is to go back into the ICS, delete the offending feature codes, and reboot the CallPilot again.