Avoid rerun when clicking on a menu entry having children?

[DirkHD-ops]

Clicking on a menu item with chilren evokes a rerun of the page.

Is there an option (maybe I have overseen this so far) to avoid this rerun?

This is quite problematic for my application as some page renderings need a bit more time and opening /closing those grouped items with a parent result in quite a lot of loading etc.