Midi Time Code from Sonar X3 stops after a couple of measures of recording

When I Set up Sonar X3 to send midi sync or midi time code through my Midi Express XT while I'm recording the audio out from my Roland G8 syntheszer and MPC Drum Machine...The recording lasts about 2 measures and then stops. When I check the routing screen on my Motu clockworks it has gone blank after the recording stops. I have to close Sonar and re-open it for the clockworks screen to return to normal. The MTP AV that I have acts the same way with this new computer I have purchased. I had no problems for years when running Windows XP. When I run Sonar X3 as a slave it picks up MTC no problem.?  I have upgraded to a new pc with an i7 processor running a 64 bit operating system windows 8.1 with 16 gigs of ram. What could be causing this problem?
I have tried everything I can think of.