Checked status report and found no errors. Cleared all cache too.
Also tried with some old Views that I've created and it don't work on those either now. I've tried to disable Views Slideshow but no change. So this might be some other issue that occurred before I installed Views Slideshow.
Using D7, Views 3 and Views Slideshow 3.1
EDIT: It turns out that it's all settings that can be done from checkboxes are disabled somehow. I've even re-installed the Views Module but no luck. Don't know what's causing this behavior.