(re)Activation problem

have just started notion3 for the first time in a month and i get a window saying that the software requires activation.
have entered my licence number and email address, clicked activate, and get a message that this licence number has already been used.
what's the story now?
thank you in advance
míchéal ó c
macbook pro 2.2 GHz intel core 2 duo
osx 10.6.3
have entered my licence number and email address, clicked activate, and get a message that this licence number has already been used.
what's the story now?
thank you in advance
míchéal ó c
macbook pro 2.2 GHz intel core 2 duo
osx 10.6.3