top 404 from logs

themes/garland/style.css,/drupal/sites/all/modules/fcked ...

comes up as the top "page not found" in the logs. It looks as if the "," either shouldn't be there (i.e. the comma plus what follows it shouldn't be there), or isn't being recognised. This isn't impacting on the site but it would be good if we could get rid of it. I'll look into it.