After posting here last week I got some great advice on how to adjust my lever brakes. Today I got the guts to try it. Everything seemingly worked out great until I went for a test ride to squeeze them a few times and I notice that I got a rubbing sound after a few times. I went home and noticed that when I applied pressure to the brake handle one side of the brakes moved quite a bit and the other side moved just a little. I could move the brakes to where both were equally away from the rim then squeeze. They both went to the rim but when I let up on the brake one side moved away and the side that isn't moving freely stayed close. Any thoughts? My type (though not the actual ones) are in the below image.

It would seem to me that this would be a common problem but I can't find a thread on it.... though I know there are probably many.

Rear brake, by the way.