Sorted!!!!!
In Run-Time settings it appears that on the Citrix 'Synchronisation' settings there is a 'Bitmap Polling delay' - this was set to '0' which works fine on the previous client - However by setting it to '1' I was able to ensure the synchronisation was refreshed! This field is described as follows:-
Bitmap polling delayThe delay between polling screen state during bitmap synchronization, in milliseconds (0 - use Citrix Client notifications instead of forced polling)