Have you pulled all 3 CR's from the CRA's? Perhaps there is something on them that you are not aware of that is effecting you adversely.
If I get this right in Feb. 2007, you had only 3 credit cards with a combined utilization factor of 80%(40,000/50,000), and now that utilization factor stands at 40%(20,000/50,000). From what I've learned here 40% utils can still effect you adversely.
But certainly(I would think) that your scores would have fluctuated slightly.
By the way, what are the scores? There's so many variables, that without detailed information, it's hard to issue any kind of a valid opinion. And that's just my opinion.