Dropdown Animation Causing "Jump"

I have a dropdown animation set on my menu which works fine, however it seems to be also effecting some tabs which I have in the same menu.

When you rollover the tabs (within the menu) they should just appear (as they do when no animation is set to the menu). However with the animation set on the menu each tab you rollover the menu looks to try and close and then reopen when you rollover the next tab.

Is there a way to stop this happening.