Was it shortened?

During the Christmas holidays, VIETNAM was on cable and I only got to watch 2 nights.

When I got home, I got out the DVD that I purchased a number of months ago, and started to flick through to see where I was up to.

So here is the dilemma - on cable it ran for 1.5 hours. I had 3 DVD's; 2 with 4 eps and 1 with 2 eps. While watching the DVD's, each ep was approx 40mins (41 or 42 mins) long. When I put in the second DVD, I had seen up to the end of ep 5. Adding the time together it would be approx 3hrs, 20-45mins, but I had only seen 3hrs on Cable.

This means that it must have been shortened. Can anyone clarify?

Thanks