Hah, reminds me of what happened to us when we were running to make the gate from the disaster that is the Schengen to non-Schengen transfer passport control. That took over an hour and when we got to the UA gate they asked about the sticker, and I said the same as the OP, what sticker? However, the guy took mercy on us when I explained we were in line for an hour at passport control and were late. He asked us some questions and gave us the sticker so we could board. Yes, the secondary security line was 40 people deep at least that time too.