Well, In any game I open or play or create now my character walks down without touching a button.
If I press the left arrow key it starts moving to the right.
WTH is wrong?
No scripts were added at all.
My guess is that your character is having the Down-syndrome (http://"http://en.wikipedia.org/wiki/Down_syndrome"), try having a good conversation with him or increasing his happiness.
Perhaps there's something wrong with your keyboard? I tend to have the walking problem sometimes with other games I play as well, including on my Xbox360, I have no idea why either.
I've had that problem too once. I think I fexed it with one of the settings in the F1 menu, but I not sure.