I've recently tried importing OpenGoo calendar ics files into Google Calendar and Microsoft Windows Calendar (Vista) and have observed the following issues.
When exporting an individual Workspace ics calendar file from OpenGoo into Google, Google generates this error.
Processed zero events.
Failed to import events: Unable to process your iCal/CSV file. The file is not properly formatted..
Error at line 15: A recurrence rule MUST contain a FREQ rule part.
I was able to import the same OpenGoo ics file into Microsoft Windows Calendar with no complaints then export it back into Google successfully.
Exporting an OpenGoo Calendar ics file for "All" Workspaces into Google worked with no error, however, OpenGoo is throwing errors for both individual and All Workspace ics calendar exports.
Error
Ext.get("og_1237825821_660603cal_exp is null
In addition, several deleted events in OpenGoo are appearing in both Microsoft Windows Calendar and Google after ics import.
There is also 1 recurring event in OpenGoo that still shows as recurring after import into both Microsoft Windows Calendar and Google "after" being changed from "Repeating Daily" to "This Day Only".