Our apologies for these issues. When saving the file, you'll need to rename the file to a .ics extension rather than .asp. This should do it. The format of the file is correct, however the extension is not. We're aware of this bug and hope to resolve it soon.
Additionally, you can get an iCal file for your entire calendar by going to My JamBase > My Calendar and clicking on the ICAL icon in the bottom left hand column. This file, too, needs to be renamed to the .ics extension. Then I believe it can be imported into Outlook.
Hopefully this will work for you. If you're having troubles beyond this, please contact us from the bug form: http://www.jambase.com/bugs
Hope this helps,