This is happening because the formatting for the page is cached seperately from the words on the page. The formatting was changed for the current new page, however your browser is using the old cached version of the formatting.

You'll need to figure out how to refresh the cached data that's being used. For windows explorer there's an option under tools/internet options/ to check the webpages for changes on every access. Most browser don't check the formatting everytime it's loaded in order to speed load times.