I tried the latest version of the event_calendar module with a fresh install of Silverstripe 2.4.7 (installed dataobject_manager and uploadify first). It wouldn't install correctly so i tried again in dev mode. When doing a dev/build i see a lot of errors about finding double classes. Not something i can resolve myself.
There is no older version of the event_calender i can get working without major errors. Is there a combination of versions(silverstripe, dataobjectmanager, event_calendar) that will work? Please let me know.

At the moment I have the 2.4 branch from github working (with the master branch I got the error about the double classes). I have to manually fill in the dates (my locale is nl-NL) like 4-juli-2012 or i get an error about not filling in the dates correctly.
Is there a way that I don't have to fill in the dates manually??

There was also an error about "index of Calendar not known" in CalendarUtil.php when trying to look at a calendar page.
After changing line 97 in CalendarUtil.php from "$template = _t("Calendar.$key",$lang['en_US']['Calendar'][$key]);" to "$template = _t("Calendar.$key");" it seems to work, but I am not a programmer and don't really know what the consequences are for this change.