Yes, unless the limit screws are incorrectly set, I'd say you have a cable tension issue. I'd start over by checking to see if you have all of the slack out of the cable (i.e. loosen the pinch bolt and reset the cable). Make sure you derailer is in the correct position when you do this. Then run it through the gears & check the alignment & turn the barrel adjustes as needed. Or, just hit up you-tube for a tutorial. Step 3, take it to a shop.