How to set the single click speed?

[Jim Byrnes]

I moved from Ubuntu 12.04 to 14.04 and find I have trouble getting drop 
down menus in the title bar to drop down.

If I click on a menu as I normally do it just flashes briefly but does 
not drop down.  To get it to drop down I must tap and release the button 
very rapidly.

I've googled and checked various "settings" programs but can't find a 
solution.

Regards,  Jim