It works!
My wma lossless files play on the correct speed and are bit perfect.
I already uninstalled Foobar, there is no need for an external player anymore.
The 'no sound from digital output' issue is indeed caused by the M-Audio driver, I now use Asio4All permanently.
Still i have one minor issue to report. When I skip to the next track the sound stops shortly and plays a small part of the skipped track before the next track is started.
so reading your posts and the replies i got from others i don't think that i can be of much help to you.
looks like to be a problem with your ound card drovers itself.