Please check the time zone settings for the server, your host and the ClientTimeZoneId property of the ASPxScheduler. If they are the same, you shouldn't experience the time difference. You can open the resulting .ics file in any plain text editor and check for the TZID attribute - it indiicates the time zone to which the appointments belongs.
If the problem persists, please ask our Support Team for assistance - use Support Center at http://www.devexpress.com/Support/Center
Regards, Brian.
R&D, .NET Team, Developer Express Inc.