I get this sort of message all the time on MySpace:

Making Me Nervous won't play when I add it to my profile :( I just discovered you (thanks pandora. com!!!) and I want my friends to hear how awesome this song is. I see from your comments other people have had the same problem... can you fix it?

I searched all over and I can see lots of people successfully have added my songs to their pages and couldn't find any info on why it might be failing in some cases. Does anyone know what the issue is?