I was trying to look at an item on the Costco web page. As you can see from the image "Pop-up being blocked" the size selection is missing. I guessed and allowed pop-ups from Costco.com. As you can see from the image "Pop-up setting allow pop-up" the missing data is visible. I thought Firefox would prompt if pop-ups were being blocked giving you the option to enable them. Am I wrong? How is a user supposed to know that there is missing data being blocked by Firefox?