Sorry to bump up this old thread, but today, ads started popping up again but I have Premium. Something wrong with my end or is it something I downloaded?
That definitely sounds like you have some type of malware infection; I would suggest scanning your computer immediately. You should see no ads of any type as a Premium user.
Just an update: I installed Anti-Malware software and backed up my PC as an added measure. After about an hour of scanning, everything seems to be working normal again. I don't see those ads anymore.