1) login to SOGo
2) open "Calendar"
3) click on "New Calendar..."
4) create a calendar named "A"
5) click on "New Calendar..."
6) create a calendar named "B"
7) select calendar "B" by clicking on its name
8) select "Multicolumn Day View"
9) choose "personal calendar" and "A" for display
10) right click in column "A" and click on "New event.."
=> the new event will be created in calendar "B"!!!
That is not, what a normal user expects.
Instead the new event should be created in "A".