iTunes downloaded m4p files will not play???

hey guys, I love the software! it is perfect for what I need as a beginning DJ. I downloaded the free software version and started dragging and dropping downloaded songs from iTunes into the UltraMixer and it would send me this:

[color=#FF0000:56c10] [b]Error: Could not load file C; UsersOwnerMuusiciTunesiTunes MusicJustin TimberlakeFutureSex_oveSounds02SexyBack.m4p.[/b[/color:56c10]]

this is very frusterating since 5,500 of 6,000 songs from my playlist are purely iTunes downloads in m4p format.

How can I get your program to play iTunes downloads in UltraMixer?

much thanks!