Wrong panel size for Resources->Calendar view

Current Situation

• The default panel size for the Resources->Calendars view is calculated too small, see screen_01.png.
• This problem occurs if the root folder is hit a number of times. For the first time it works, subsequently hitting the root folder results in a wrong panel size. Testing has been performed with some 5 calendars.

Desired Behavior

• The panel size should be calculated correctly.