Do you have two pairs cross-connected to each phone? Also, don't forget that the station output from the KSU is for three pairs per station, so you must skip the third pair per station connection.

Hint: The first pair of the station port feeds the XDP jack. The second pair of the station port provides the digital connection between the phone and the KSU.

That should be all that you need.

Ed Vaughn, MBSWWYPBX