I can no longer click on certain things in firefox. Sometimes if I reload the page I can click, but that doesn't always solve the problem. This is most common on things like facebook, the birthday and event tabs. If I click on them nothing happens, but sometimes when I reload the page it works. I have noticed this is mainly when it involves things/links that open a small drop box that you have to click or enter information into.

For example, the drop box that allows you to write on people's walls when it's their birthdays. Or another example is on my company's website. If i want to pick up a shift, I click on this button that says pickup shift and then a drop box comes out that says "enter comment" for my manager.