Electric drivers seat veers right on forward.

thank you. I have taken the seat out, checked the rails, nothing stuck or jammed in the rail. It is entirely clean under thre. I can't understand what is going on. I can move the seat up/down, backwards and then forwards to just about the right spot I want near the steering wheel area and it starts to veer right into the seat console and I stop moving it any further, because its ok in that spot to use.. Wondering if it might be the screw drive' although I checked it thoroughly and seems to be no problem. appreciate your help.If anyone thinks of something, please advise.