Aha, I just remembered. There is actually a problem where you click "next" and the next site doesn't show the added balance from the previous one. What you have to do then is to not close the previous tab, and click next once again. It's a known issue.
Yes I can also remember this annoying bug.
I also remember sometimes even I clicked once again on previous tab the balance was still not added.
BTW, anyone tried its referral system? Does it work or just a "scam"?
The referral system does seem to work, but payouts per offer are so low at the minute that it's hardly worth the bother.