BlackBerry :: Time Zone Update Change Appointment Times?

I would like to know if there is a way to avoid calendar appointment times changing when the time zone automatically updates. I would book theatre tickets in New York at 8pm and put that in my calendar. When my BB Curve updates the time to New York time from South African time, all my appointments also change by the 7 hour difference.

Is there a way of keeping the calendar entries at the entered time when the phone updates it's time zone. This also happens when updating the time manually on the phone.