I am recording sound files from my DAB radio usin its inbuilt SD Memory Card then transferring the MP" files to my PC. When playing these MP2 files in Windows Media PLayer there is a very feint high-pitched screaming tone. This also occurs when I burn the files to CD using Winamp or Windows Media Player. When playing the files in Winamp the distortion is not there.

You could decode them to wav first and burn that. If you have Nero installed, foobar2000 should be able to transfer them directly to CD as well. I read a post today indicating it had a fairly robust MP2 decoder, so it would be the first thing I tried.

I have some success. Am able to Edit the MP2 files with 'Cool MP3 Splitter' and burning them onto CD with RealPlayer worked without distortion. Strange

It might have something do your MP2 files being 48 kHz if they've been captured from DAB. It's possible that the resampling algorithms used by some CD burning apps to resample to 44.1 kHz on-the-fly are not as good as they could be since it can be quite CPU intensive to do it accurately.