the MB changers of that vintage are notorious for being persnickity with the
magazines. have you tried pressing the eject button while using your finger
to press the magazine around (side/up/down) ? that carrier mechanism rides
on rubber biscuits and sometimes a little misaligned, creating just enough
obstruction to prevent ejection. another magazine might be fine.

__________________
-- raymond~
47º 34'N 122º 18'W