If you're running 2200's all the way around, I have a question:

If you turn on only the 2200's powering your main left and right speakers, do you still hear the same effect?

Also, your post doesn't say what you're using for a source, but some sources have extra features which can be used to try to simulate surround sound with only two channels. If your source has such options, go through the menu(s) or switches on the source and make sure that only any such simulation options are off.