Little bug in grid

Hi,

I found a small strange behaviour in the grid that I can reproduce on the showcase : http://www.smartclient.com/smartgwt/showcase/#live_grid

I use Firefox 17.0.2 on Window 7 and when I click on the header of a column, on the right arrow, the popup with sorting option appears but I cannot close it but clicking a second time on the arrow button nor by clicking elsewhere. I must chose an option to close it. If it's not a big deal to correct, I think it will help to use the grid properly.

Thank you !