Thanks for the suggestions Dave. I did redo that flight 3 times again since my first post because I was setting up a short scenario to show my friend the PF3 program in hopes he might purchase it also. The issue did not occur the two times I flew it earlier today or the 3rd time we flew it tonight, so like you said, it's hard to say. However I'm pretty sure that the first of the two times it happened yesterday was again when I was being handed off to "radar control", but I was flying Glasgow - Liverpool that time. In answer to your question about when did it start, I'm pretty sure it was when ATC handed me off to Radar Control in the log, because I think that is when I got distracted listening to the noise and when I replied back later I was hoping my reply would end the noise and it was at that point that I started changing freq. and Com radios to see if I could get it to stop.
So, as to why it didn't happen these last three times? I don't know, maybe some kind of anomaly. But I like your suggestion about tuning ATIS if it happens again and will let you know both if it does happen again and if tuning ATIS has any effect.
Thanks again for your help here. I appreciate your support and overall coverage and knowledge of this program. I used to be in software program support years ago and I know how everyone expects you to know every answer and immediately and as you know there are so many possible causes for any given issue. You do a great job and I'm amazed at how well you know all the intricacies of this software and are able to use the bug log so effectively for analysis. In fact I have spent a few hours over time since I bought this program just reading through different postings here to familiarize myself with different issues and solutions you provided for a host of questions you get, because I figured this would be a good heads up for me if I experienced any issues and I would already be ahead of the game by seeing what others said and the solutions you offered. Again, you offer a great service and always with a kind and supportive tone. That's rare and I wanted to let you know it is noticed.
I hope more and more people discover PF3 and get the enjoyment from it that I have in just the short time I've owned it. It really makes the whole Flight Sim experience better!
Mike