Any thoughts on call fwd both or mobil ext not coming back to Inmail.

Says clearly in specs and programming that you can do this. Works fine on the 1100.

I get it to ring both but it stops ringing the cell after 5 seconds the rings about 20 secs and then goes to cell VM.
Have played with all timers, cf delay and xfer timer, and UTRF or Supervised.
Can use CF Both or Mobil Ext, just want it to end up in the Inmail.

Thanks in advance.