Directory Plugin - Listings - 404 Error

I've put in about 30 or so sample listings - we're using this as a local business coupon directory. However, if I visit the listing of coupons - http://member.athenscoupon.com/coupons/ - the first page looks great. However, if I click to go to page 2 (or even page 3) I get a 404 Error.

I'm assuming that I don't have my Permalinks set up properly, but I can't seem to find the proper way to set them up. Any ideas?

Thanks in advance for the help.