[TYPO3-calendar] Typo3 6.2 with cal 1.6.0: ical import broken

[Timo Litzius]

Hi,

I am about to use Typo3 with the cal extension for a project.
The events are stored in Google Calendar (in different calendars).
I've tried to create multiple external calendars in the cal extension.
Somehow the first calendar gets imported but the second one is always 
ignored.
After fiddling around (deleting the storage and reinstalling the 
extension) I am in a weird state:
- Adding an external calendar (or clicking save) does not import anything.
- After adding a calendar only the first calendar also creates a category
Now I am not able to import any calendar events from an external source.
I've also tried to setup scheduler (documentation is a bit unclear here) 
to trigger the import but that does not work, too. (nothing gets 
imported) I cannot add a dedicated scheduler task for "cal". Is that a 
bug or is it enough to specify the minutes on calendar creation?
And is it normal that imported events do not get a category?

Many thanks
Timo