Problem in Jquery UI Menu on hover

Problem in Jquery UI Menu on hover

I am using Jquery UI Menu plugin in my app. I got one issue. 
In sub-menu (2nd level) If I hover mouse repetitively on single Sub menu item then sometime Hover action not happened.  Explaining the scenario here :

I copied demo example from here  and added one more sub menu level under Item 3-2 .
Now hover the mouse on Item 3-2 next level come up but If I do hover repetitively then at certain point on hover the next level not came up.

To reproduce this issue follow this steps 

1.       Mouse over on Item 3 – this displays Menu

2.       Mouse over on Item 3-2  – Sub menu appears

3.       Mouse out from the sub menu – But, don’t click outside of the menu, so that Item 3 menu still open.

4.       Now Mouse over on Item 3-2 (select the same item selected in step – 2 , Do repetitively on this menu item and check) – Sub menu is not coming.

Can Someone check and help me here !!!

Thanks in advanced