For the curious we had only one year of joint tax returns (the second was filed after we applied), we did not have any affidavits with our petition either, and we did not even have any joint lease/mortgage documents since the house was purchased before we got married. We did however have lots of joint financial, insurance, medical documents together with evidence of joint travel, hotel receipts, photographs etc.
Thanks to all of you for making this such a wonderful resource, and good luck to those who continue to wait.