Dropdown in Twentyten moving everything

I am using the Twentyten theme. I created a dropdown menu but when the menu drops down it bumps everything else on the page? I was thinking maybe it was a z-index thing but I tried messing with that and it doesn’t fix the problem. You can see it here https://www.lieslswogger.com/JGHS/

Hover over the last item on the right “Current Projects” and you’ll see what I mean.

Any suggestions on how to fix would be much appreciated, Thanks!