After importing a playlist and the original is changed, the imported one stays the same!

After importing a M3U play list the shown play list in Songbird stays the same. Even if later on the original is changed. Could it be possible to keep the play list in Songbird ''up-to-date'' with the original? This worked well with WMP. As I use a lot of different programs and they all use the same playlist, I want to keep them up-to-date in all progs. This is the only thing that is keeping me from switching to Songbird.