Google Chrome is particularly good at caching the web pages you browse - that's one of the things that make it so fast. The downside is when you're doing css/style changes to your blog's theme - this includes changing the theme or it's menus and sometimes when you are updating widgets or even pages.
The solution to this is to clear your browser's cache (you may have to do this after every update) - http://www.wikihow.com/Clear-Your-Browser's-Cache
There's a nice little trick in Google Chrome to temporarily turn off the browser's caching feature while you making updates to you theme. - http://stackoverflow.com/questions/5690269/disabling-chrome-cache-for-website-development