2006 Ford Fusion No rolling back while in neutral on inclin

Recently I have been noticing a few times where my car starts smelling like the brakes are burning or transmission burning? Not sure what is happening. I still have 60% left on brake pads. Only 32500 miles. Trans and clutch still in great shape. Usually find it occurring after getting off of the highway on the exit ramp. (Which is an incline) When I sit in neutral, without brakes engaged, I expect to roll back while on an incline. Well these few times it seems as if something is prohibiting me from rolling back. And when I shift into 1st, there is some resistance? Any ideas? Or troubleshooting suggestions? Please let me know. Thanks.