FourCircle has NOTHING to do with the fact that your checkins do not appear on Facebook. Again, check and double check that you have linked your accounts and that Foursquare has the permission to post on your Facebook Wall. If these are enabled, disable them, remove persmissions and RELINK your accounts (I too had a problem a couple of days ago when check-ins stopped appearing on my wall - I, however, did what I suggested above, and everything is woking properly now).