Thank you for the instantaneous answer!
1. Arrow keys work great in Win7 RTM 64bit (thanks for the hint)
2. I overlooked the settings for excluding/selecting categories/calendars
Here are some further ideas:
Since the week-view is rather large, could you add the option to add a keyboard shortcut to toggle the visibility of a specific element (calendar, week-view, time, etc...)? This would be very handy.
Would it in general be feasible to more easily resize single elements? For example adding a tiny rectangle in the lower right corner of each element that by clicking enables the user to directly change the size of this element? (low priority)
And something a little more far fetched: What do you think of creating a printable version of the week-view? To give you an idea of what I mean take a look at this link (random data!): LINK