1st, skin the backside of the wall with plywood, 1/2" should do. Glue and screw (NO NAILS) the plywood to the studs. Go buy some construction adhesive. Don't be cheap with the screws, every 8-10 inches in each stud, run glue down all studs. 2nd, drill a few pilot holes and strew some 3"x1/2" lag bolts into the floor. The plywood will make the wall rigid, and the lag bolts will hold it to the floor. Most of the wiggle is coming from the fact that the nails are not keeping your joints tight. When you build the second wall fell free to put the construction adhesive between each joint for added strength.
r1200gs_chris screwed with this post 02-06-2013 at 12:41 PM
Reason: Big fingers