Hi, I'm have just installed Sibelius 5 (music notation software) and I'm having an issue with playback. Nothing I choose in Sibelius eg; sound files, things I create myself will play, yet if I play other music files on my PC they play fine. Anything in Sibelius just doesn't play. I get an error message telling me something about a MIDI device. I'm using XP Pro. Would anyone have an idea as to why this is happening?

Cheers