I would suggest you try the following: With everything assembled and locked down, and the blade backed into the plane just enough to keep it from cutting, back the lever cap screw out to the point that everything is obviously loose. Tighten the screw down to the point that the lever snaps down firm but finger tight. check the lateral adjuster and the depth adjuster to see that they are firm but not difficult to adjust. Keep in mind that the depth adjuster will normally have some slack (lash) between pushing the blade in and out. You want to keep the depth adjustment knob placing pressure against the blade as if you were advancing the blade out. If you need to retract the blade, adjust it back and then turn the adjuster as if to push the blade back out. The pressure of the adjuster mechanism against the blade should keep it from backing out if the blade is sharp and the depth of cut is reasonable. If all else fails find an experienced woodworker locally to go over this with you. It shouldn’t be a difficult thing to get the hang of. Just continue to play with it and you will have it in no time.