404 Errors

I get a lot of 404 errors at: http://www.woodlogger.com/2013/04/hummingbird-feeder/

and the error is:

/ct5.addthis.com/static/r07/widget114.css

I see this when I review my logs. The page appears to work okay though. Any idea what’s up with this?

I’ve also seen several of these 404’s on various other pages on my site as well:
/ct5.addthis.com/static/r07/widgetIE67006.css
/ct5.addthis.com/static/r07/counter013.css
/ct5.addthis.com/static/r07/counterIE67004.css
/s7.addthis.com/js/300/addthis_widget.js

http://wordpress.org/extend/plugins/addthis/