i know it’s a year after you posted this– but i just encountered the same problem and fixed it by trashing my prefs (after backing them up, of course)
navigate to
User Account> Library> Preferences> Adobe> After Effects
just option+drag it to your backup location, then drag it to your trash bin. restart after effects, and enjoy a blur-free render (i hope).
creative editor
http://www.cutteredit.com