the zone change from the SO you have install and the language, maybe it's  better the infragistics correct the bug checking when load the zone in the combo if the zone already exits in the list. I have the same problem and after update of windows I have the same problem again.it's not a good solutions we must take the source and debug the problem.

I changed the key registry but i have always the same problem.

Help Please

I confirm you are right. I use a french windows XP and found this kind of problem here :

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Arabian Standard Time

change Arabie in the std key to Arabie2

Many thanks for your help, now AppStyList works fine.

I was not able to get any help from Infragistics Tech Support, so I had to debug the problem on my own.  Based on the backtrace, I guessed that there were two timezone entries with identical names, and this turned out to be the case.  Using regedit to change the name allows the AppStylist Editors pane to work.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mexico Standard Time 2

Change the value "Mexico Standard Time" in the Std key to something else.  I just added a "2" at the end.