I too have tried to no avail to get this fixed. I have tried everything from this thread https://www.ads-software.com/support/topic/plugin-all-in-one-event-calendar-import-and-ics-feed-dont-work?replies=32 and can only conclude that version 1.5 is well and truly broken for iCal feeds.
Has anyone had any joy getting a response from the developer?
WordPress version: 3.3.2
All-in-one Event Calender version: 1.5
