If you have any weird browser problems the first thing to do is to clear the browser cache and reload the page.
You could also try clearing the cookies but remember that if you clear all cookies you will lose saved passwords. You could clear only the cookies relevant to the particular site.
A google search should turn up a page that tells you how to carry out the process with your particular browser. Of course, software developers LOVE changing stuff so it can be annoyingly tricky to find the process for your exact browser version. Don't be too surprised if the process described does not match exactly.