Menu selection on a Tablet

Hi,
I have a menu with e.g. 3 main-menus and each of them have 4-5 sub-items. While the menu selection works great on the Desktop the menu selection on a Tablet has serious problems.

On a desktop I can either hover or click the mouse and then the sub-menu will be displayed. On a tablet I can only click on the main-menu to display the sub-menus. But if I click on e.g. main menu B than the link is opened and loaded. If I click after this again on menu B than the sub items for menu B are displayed. The sub-menu is only than displayed – in no other situation.

I can change the Menu-behaviour for Tablet to be the same as for Smartphone, i.e. with 990px. But is there a chance to adapt the behaviour for Tablets that it displays the menu when clicking on the menu?

roland