I used pro tools to encode them to mp3 for a small file size
and never heard anyone have this issue.

That theme has been out for while now also.

If you want to encode them to wav go ahead
I don't mind what you do to the theme at all.

Really would like to know the answer tho...
Try and encode them to a different format of mp3
and post what format you choose if you can.

Thanks

Edit:
I reconverted them for you in different format.
http://www.modleague.com/immortal/designed4_updated_sounds.zip
Try these out...