Strange behaviour "view all"

There's a bizarre but obvious problem with the behaviour of my "event" module, I'm pretty surprised not to see something similar treated here - I hope anyone will be willing to help me out.
In the calendar view, as soon as I click the "view all" button, the calendar simply turns blank! at this time, I have created one test event + a second content type (vacancy) which could function as an event and one node of this last type. since I feared it was the interference of several events or event types that caused the calendar to go blank, I deleted both the latter. even with one single event, things remain the same. view all equals "nothing to see" on my site!
as said, this is an obvious problem and I wonder what I'm overlooking if no-one else has brought it up yet.

kindest regards,

Joris