As a general tip, mixing physics with other movement behaviors is a bad idea.
It's hard to say what could be going wrong in your project. I can only guess but your player might have a lot of empty space around it in the image file, which is accounted into the sprites bounding box. So you either have to get rid of the extra space around the player or set the player collision to collision polygon aswell.
If it isn't that you'll have to post the project file.