Drop Down Menu Disappears upon hovering

Everything on the site is perfect, and perfect when viewed in any browser on a MAC but on PC the drop down menus are hard to hover on, they tend to skip or disappear – not sure if having modified spacing in editor caused this problem as it was fine initially and is there a way of fixing this.

When you hover on main tab – drop down shows, and u want to scroll down to the drop down tabs, the entire drop down box goes away, not letting you make a selection.

please help