Hi Snel pUppie,
Might be very late on this - But, I have a solution!
I had a requirement similar to the one you have had. I wrote a simple jQuery snippet to get Drop down menu when I click on the Parent menu.
Once you click on any of the parent menu - it will show its own sub level in the drop down.
When you click on any other Parent - the previous Drop down will disappear and the new Drop down will appear.
I have that tutorial here
Since I'm new here & not allowed to post links - I'll put it this way ultimatewebdevelopmenttutorial - This is my blog.[Please apend ultimatewebdevelopmenttutorial with .blogspot.in]. Put it together and put it into the address bar and hit enter or search on Google
It is a bit static type - but much useful. Any questions - please feel free to put it here!!
Thanks!
Stormstriker Sumesh