Why can't I re-install Songbird?

I downloaded Songbird and set it up, it worked and everything was fine until I moved my itunes. I couldn't get them to play, and tried to import them into Songbird again, but the import kept hanging. I thought I could uninstall Songbird, then reinstall and it would fix the problem, but now I can't get it to reinstall, it just keeps telling me there's already a version of Songbird on my computer. I've searched for anything with the term songbird in it and have removed all I can find, but it still insists I already have an older version.