If the guy told you there's only four seasons, then he's wrong ;) There is a fith season. It's just as long as seasons three and four and some of the episodes are freakin' nerve wreaking! :)
Thank you for your replies christiannyblom and imcool14. I plan to order season 5 to complete my set from Movies Unlimited. It just goes to show that many of the young (even teenage) clerks who staff such stores as Sam Goody have not been trained properly and/or just don't care enough to learn about the merchandise. I know I can always depend on my many friends on IMDB to give me the correct information. Once again, thank you.
yup, mine finally got them in, found s5 for $8 at Big Lots, s1 and s5 at Walmart for ...$12? I know it was a couple bucks more, and not all WMs have them.