Do you talk to him when he whines, or make a big issue of it? You could quite possibly be encouraging it??
Benjamin is a talker/whiner/howler you name it! Before Maddie came along, and before I knew better I'd talk to Ben all the time. NOW I'm trying to encourage with all I have, quiet behavior. It's my fault and I know, but I'd just like to warn you. He doesn't whine due to excitement or stress he whines to get your attention, he whines while he's eating, he whines during play, he talks to you when you ask him to sit, he talks to you when you talk to him. Just about everyone loves it and finds his constant whines, and woo woo woos so endearing. I find them annoying.
I'm in no way dismissing the previous posts, just suggesting you watch encouraging it or drawing too much attention to the behavior.