capture one 3.7.1 on OS X 10.2.8 trouble tethering 1Ds mk2

hi, finally updated from older version of capture one to 3.7.1 latest build that will run on 10.2.8 after purchase of 1Ds mk2.

my old 1Ds body will work tethered no problem but the 1Ds mk2 body will not connect.
the software tries to connect but comes back with connection failed.

any ideas much appreciated.
cheers
nigel.