I have JNPG with a skytrak. I am able to use all modes of play - except for 2 X 4 man scramble, or 4 X 2 man scramble. When I try either of these modes everything starts up normally - the red dot appears on the mat. When the first ball is hit - the dot disappears and the system hangs. I have checked all the obvious things - and as I said - I have no problem with a 2 X 2 man scramble - or 8 man stroke play, or other modes of play. Any help would be appreciated. I purchased the software primarily for the ability to have 2 X 4 man scrambles - so its rather frustrating.