Interesting. I think I have run across this before. It has something to do with 1a2 emulation and reserving an analog trunk to a boss group. I think the trunk has to be reserved to a boss group, the phone has to be assigned in that group (ringing or not) and then the line key like 7100 etc put on the telephone. I saw this on flexsets ONLY as an issue and not DKT's in a mixed environment once.