Base Map/Theme Control extends below browser edge

Is there a way to manage how the basemaps and themes are displayed in the Basemap Control.

I have many base maps and a few themes. When The control is 'opened' it extends past the bottom of the browser. The Blue edge in the image is the edge of the browser. The Basemaps control extend past the bottom of the browser. 

/customer/servlet/servlet.FileDownload?file=00P6000000eltvdEAA

I was hoping the new layer control would fix this but it does not. I grouped my base layers into a folder in the layer list, but that does not come over to the Basemap Control.

/customer/servlet/servlet.FileDownload?file=00P6000000elzH8EAI

Are there any ways to stop the Basemap list being cut off.