moonshineshadow: Hmm... did you try clearing your browser cache after logging out? There was one other guy who said that he could only get the second stamp by going to a different computer... So try clearing the cache, if nothing helps, wait a bit to see if gog can fix the bug or else write support that the method they proposed is not working :-)
I just went to a secondary browser instead, but basically the same issue.
If need be there "should" be proof that I was here on day one since I collected the Free Mount & Blade promotion, got the order confirmation and everything. While that isn't proof that I collected the stamp, that's the best I can offer.
So I'm fine with waiting. I'll only ask about it if I make it to the final day. After all, if I do miss a day for real, then there's no point in bothering them about it. I'm just posting to make the case known beforehand. And on the minor chance someone else had this same exact version of this problem.