Look at the above images and try not to curse loudly. Yes, for some unknown reasons, market share of IE6 and Windows XP went up just a bit in January. The marketshare of IE went up to 8.38 percent (according to arstechnica) in January (from 7.66%) while Windows XP's marketshare went up to 47.19% from 46.52% (as per Cnet).
Another big surprise is that IE ate into Chrome and Firefox desktop browser marketshare in January and this is the first time that Chrome's marketshare went down (since its release). Safari maintainted its lead in mobile browser marketshare while Opera Mini's share is sliding fast (might go below Android native browser's share by end of February).