when I do an export of a calendar, all dates are indeed exported, except recurrent ones.
I have done some testing until now and everything seems to be working ok. The *.ics file that I exported dumped all the dates I have put into my calendar. But when I added a repeating date (a weekly meeting), only the first date was exported.
I also tried the very cool php code from sadysta
http://forums.opengoo.org/index.php?topic=1128.0 that exports calendars "on the fly" and I got exactely the same issue.