I am in the process of replacing some of the wood trim in my home. Some areas on the sheet rock does not have 2x4 reinforcement to nail to. How would you suggest I install the trim with? It seems that when I use the trim nails they will not hold the wood flush against the sheetrock.

Ordinarily the trim is nailed to the 2x4's in the wall. If you are having trouble around a window, the trim is often nailed to the window frame. There should be 2x4's framed around the window. There should be a 2x4 either right next to the side of the window, or within an inch. Look for the holes where the old trim was nailed on. If you need more help, write back giving more details.