Problem adding to a storyboard

[Gilligan]

Hey... I know this seems simple as hell but I can't do it.

I looked at the help file and I see that it shows I should just drag and drop and a green "+" icon appears... this does not happen.

It just lets me move it around... I get a red "x" if I try to put it else wheres... where I shouldn't basically. But no green "+".

This drives me crazy... I've tried this in 3 different browsers and still NOTHING.

A little help please.