Problem in JQuery ui Menu links when the user press Space or Enter key. It works with a mouse click.

Problem in JQuery ui Menu links when the user press Space or Enter key. It works with a mouse click.

The 'Enter' or 'Space' key is not opening links in the jQuery UI menu. How can I get it to do this
I tab into the menu in my browser and I can move around with the arrow & tab keys just fine, but if I want to open an active link I have to use the mouse...I can't just tab to a link and hit 'Enter' to open the content.
 
I have search in this forum and found that other users also has this problem, but I have not seen any solution of the problem so that is the reason why I created a new issue in this forum.
 
Thanks in advance...