Guys, first of all, thanks again for the great tool!
I've just discovered a bug, when on a moderately complicated diagram changing a to-state of a transition from one state to another causes PlantUML to draw crazy things (like overlapping states, for example, and more). You can see for yourself:
GoodTrans.txt - all OK
BadTrans.txt - not really (transition to-state in the S_Editing_OverviewOutdated state upon E_FinishEditing changed from S_Viewing_OverviewOutdated (as in GoodTrans.txt) to S_Viewing_OverviewOK).
GoodTrans.txt is at https://dl.dropboxusercontent.com/u/1002362/GoodTrans.txt
BadTrans.txt is at https://dl.dropboxusercontent.com/u/1002362/BadTrans.txt
This is with version 8019 (Apache License). The server verison on the homepage doesn't seem to like BadTrans.txt either.
Perhaps you could take a look. Thanks!