Selecting Object Problem

[Anonymous]

Hi! 

I am using Motion Builder 2012 for quite a long time now and it's the first time I encoutered this:

Whenver I've already selected an object I can't deselect it by simply clicking outside of the object or clicking/selecting another object. What do you think is the problem? I can still work on the files I have but it's becoming a problem. 

Thanks!

[doodski · Accepted solution]

try shift+d (using maya controls)