i was just trying out the demo and probably found a little bug. If you change the timezone of a calendar entry (i changed from GMT + 1 to GMT), then everytime you double click the entry, edit and save, it will be listed one hour later, if you do not edit the time.
Don't know, if this is the right forum to post this, but i hope, that helps you increasing quality of this (my first impression) nice software.
Excuse my bad english, but it is late and i'm not as much using english as i should :)
Hmm. I just tried this out on the current build and everything looks OK.
Note that in the scenario you describe, the time in the edit dialog will read one hour off from the time in the Calendar view -- but this the correct behavior as the edit dialog time is now being specified in a different timezone from the Calendar view.
IE, assuming your calendar is rendering in GMT, then the following steps:
1) Create an appt at 3pm GMT, save it.
2) Look at calendar, see appt at 3pm on calendar
3) Edit appt, change timezone to GMT+1, save
4) Look at calendar, appt now appears in the 2pm block
5) Edit appt, notice that the dialog says "3pm" and "GMT+1"
....I think this is what you are describing -- and it is the correct behavior. The modified appointment draws in the 2pm block b/c it is specified at "3pm GMT+1" ---> which is 2pm GMT. When you open the appt for editing, you see the full specification (3pm and GMT+1)
Let me know if I'm misunderstanding you somehow.