Just to add, I'm seeing the same issue (no launcher on an external monitor in mirror mode) on two machines:
Dell Inspiron 1501 (AMD Turion 64 X2 Mobile Technology TL-50, ATI RS482 [Radeon Xpress 200M] and also Dell Inspiron 6400 (Intel Core 2 T5200), ATI M52 [Mobility Radeon X1300]
Just to add, I'm seeing the same issue (no launcher on an external monitor in mirror mode) on two machines:
Dell Inspiron 1501 (AMD Turion 64 X2 Mobile Technology TL-50, ATI RS482 [Radeon Xpress 200M] and also
Dell Inspiron 6400 (Intel Core 2 T5200), ATI M52 [Mobility Radeon X1300]