It has happened in the past, when they were updating the site. I can log in just fine, and there wasnt a message telling us of site maintenance...but again, that doesnt mean anything. I know there were times when I couldnt log in and others could, so again, it might just be some sort ofmaintenance for a smaller group of pubit users. 
It never lasted more than a handful of hours, so if you can, be patient.
