Sonar X1 Studio doesn't like to start playback or record

I have just upgraded from Sonar X1 LE to Sonar X1 Studio and have began to notice a disturbing trend.
Sonar is increasingly hesitant to start playing. This occours in both playback and record modes and is evident when pressing the spacebar or transport button in playback or when hitting R or the record button when recording.
 
It requires repeated pressing of the keyboard or mousing the record button to start play or record after which the cursor may advance only one beat at a time until it finally gets under way.
 
I am placing no great demand on the system, just a couple of midi tracks and three of audio. I had no trouble running X1 LE. It all began after I installed X1 Studio.
 
I am running Windows 7 64bit with 4 GB Ram. Has anyone else had a similar problem and fix or am I on my own. Did something change within my system, apart from the upgrade. When I looked all the settings in Preferences, they seemed to be the same with the same latency setting.
 
Obviously this is pretty frustrating and not greatly conducive to doing any constructive work when fighting the computer.
 
Cheers Wal