Sub Menu Falls off screen

Hi,

One press is a great theme thank you so much!

I have found an issue with the menu though, when there are sub items under a menu item to the right of the screen, the sub menu items fall off the screen. PLease see this issue in action by going to http://yogadharma.co.uk.gridhosted.co.uk/ and hoveing over the ‘Teacher Training’ then 200 Hour ‘Teacher Training Dates’ sub menu item.

If you have a huge monitor you may need to decrease the browser width to a more normal size like 1024px.

Is there a fix for this issue that I can implement myself?

Thanks,
John