Why does calling GetCue from SoundBank never return a cue?
In your XACT project, you may have set a sound bank property called IncludeCueNames to false. For each sound bank in your project, this property must be set to true. Open XACT, load your project, and click each of your sound banks in the project tree view. Check the value of IncludeCueNames in the property pane as you click each sound bank. If any of these values are set to false, set them to true and rebuild your project.