The only known browser I know of that occurring, since it happened to me, is Internet Explorer. So,.. don't use that if that's what you're using. Use a more sturdier browser such as Mozilla Firefox, Apple Safari, Google Chrome, and Opera. Or some other non-important browser out of the many out there.
Viva la gogogo. Switch those browsers.
If you're already on one of those browsers (even with Internet Explorer), it stopped doing that for me after a quick reboot of the computer. But make sure you do what Zet said and clear your cache and cookies anyway as they are important to clean out when things like that happened since they're usually the source of the problem.