I have a 7200 with an MCP on 4.46i.

I have current SMT-i5220's on 2.12 that connect fine, but any new handset with 2.31 software displays invalid user id on the handset (which i know is correct). I cant tftp downgrade the v2.31s as they are looking for a file smt5220s.xml ? and not the usual smt-i5220.conf that you handset looks for in V2.15 and 2.12 i cant upgrade the system as im at the limit for an MCP?? Im stuck me thinks?