Works fine for me Jimlad, I don't think a monitor could affect this in anyway so most likely it's just a coincidence.
I would try clearing your browser cache. In Firefox this would be at: Options > Advanced > Network > Offline Storage > Clear Now. The cache is made up of pictures etc your web browser saves from frequently visited websites to make page loading faster next time you visit, most likely one of those files got corrupted or something.
or press CTRL+SHIFT+DEL

