Can't add vibrato, whammy etc.

Can't add any of the articulations from the "guitar" palette. I can select whammy, vibrato, bends, etc. and my cursor changes but they won't apply to any of the notes in the score, either by clicking or pressing enter. Anyone else have this issue?
Running MAC OS 10.6.2, Intel Core Due 3.06ghz, 4GB RAM
Running MAC OS 10.6.2, Intel Core Due 3.06ghz, 4GB RAM