When starting a new Formant sythethis, the lexicon is not read correctly by Wavesurfer. This results in the user not being able to use the uppermost toolbar (File, Edit, etc.) and he/she cannot right or left click on any area of the panes present.
This can be fixed by canceling the lexicon reading, by clicking on the lower bar.
http://www.youtube.com/watch?v=TwP--XiDEiI
Video of bug, as explained by André Stenlund