I am now running FSX under Windows 7. I use Live cockpit and RC4 together.Under XP, I had no problems but now if I change FSX parameters during flight (e.g. change to real weather or increase scenery settings) RC4 becomes very sluggish on return to FSX and there is a delay of 30 secs or more in initiating a call and another 30 secs in getting a reply. (The same happens sometimes to Live cockpit as well).I know the answer is not to change anything during flight but wondered why this is happening and what can be done to correct it

I found the answer elsewhere . The problem occurs when the sound delay setting on FDC Live cockpit is set too low. Setting the reply delay to 1 second cures the problem.