I can fantasize (or should that be empathise...or sympathize) with you, PP.
The sound card was my first suspect

and that was why I decided to try a CD and SKYPE - don't know if the logic is right there, but I figured that because they were working okay, it must be the errrr...the ummm...time to call the pprune team
Oh well, at least I've got the latest update of Windows MP10 installed.
They say it's usually the simple things that cause the problems, and I think I qualify as that!