Hi,
A bit off-topic, but do you use the now decommisioned Windows Moviemaker for editing? Ask because i did, and started to suffer from some high pitched creaking sounds, distorting the original sound...which i experience in your movies as well. Might just be my computers, but doubt it since i use 3 different ones here. (I´ve since switched to the free "Videopad Video Editor from NCH, which is somewhat similar to Moviemaker as far as "ease of use" goes, and doesn´t have that unfortunate effect on the soundtrack).
Yes I do use Moviemaker but have poor hearing so I haven't noticed any sound problems so I asked my wife to check and she can hear it. I am not very good with computers so tend to stick with what I know but I will try your suggestion and let you know how I get on.
Take care.
Tony.