I am attempting to order books from Baker & Taylor. Occasionally I will receive pop-up messages specifying that a book is in another cart, and confirms that I want to add the book to a new cart. When the pop-up is blocked, I initially have an option to select "Allow pop-ups from this site". For awhile it works properly -- the pop-ups appear, and I can then override the warning and add the book to a new cart. After a few of these instances, however, the pop-ups get blocked again and I once again am given a list of options for how to deal with pop-ups from this site. However, this time there is no option for "Allow pop-ups from this site." There is an option to allow this one pop-up, but nothing in the pop-up works. The button in the pop-up to add the book to the cart does nothing. I've tried: -Disabling Firefox's pop up blocker -Disabling AdBlock plus -Clearing my cookies -Making sure "Warn me when websites try to reload or redirect the page" was unchecked (it was) -And finally, I just reset Firefox altogether. This initially fixed the problem, but it came back after about a dozen pop-ups. The problem isn't present with Internet Explorer or Chrome. I'd rather not have to use either of those, but it's looking like I don't have a choice since it seems nothing will fix this.