I'm using the free Venture theme with drop down navigation menus. These have been working perfectly for the last 6 months but now seem to work when they want to.
The worst effected browser is Firefox but I have noticed it in Chrome as well.
When you first enter the site the menus work fine then the drop effect stops working and the navagation bar is just a set of links to every product in that section.
Clicking on a few links or refreshing the page sometimes brings the menus back but mostly not.
I've tried clearing the browser cache but this has no effect.
Any ideas what the problem might be?