Wrong file!!

Yo dudes..im havin a problem listening to some of my wav samples in the load menu..the samples do load and are playable once loaded, but i just cant prelisten. before it loads it says
Wrong file!!..So there must be something with the header or the file conversion app that is wrong..soooo my q is; is there any converters outthere for Mac that will convert to Mpc wav standards without any problems..thanx

maube this helps u out. the application is called SWITCH and it's a file conversor.

http://www.nch.com.au/switch/plus.html

peace.