If you’re having problems syncing with Dropbox right now, you’re not alone. Dropbox’s services seem to be experiencing trouble uploading any new files (though viewing existing seems to be working for now). Dropbox’s status page doesn’t give much info, but does report they’re having some technical issues and believe services will be back in the next hour. You can watch for updates on the @DropboxOps Twitter account.
Update 8:10AM MST 1/11/13: @DropboxOps just announced all issues have been fixed and all services should now be working.