Maybe the return springs are getting weak or it's freezing on you from the cold. Backing up usually tends to break it loose better than going forward if you didn't know that. I use mine on a regular basis even though I have an auto and I haven't had any trouble yet. You could also try spraying the cables with something and be careful you don't get anything on the brakes or rotors.
Yeah the first time I noticed it was when I was backing up, car felt like she didn't want to move... And then when I was going foward, horrid SQUEAAAK once in a while. People look like I broke the car. In like 5-10 minutes it'd unstick though.
Thanks for the suggestion, maybe I'll try that if it's warm enough.