Privacy Fence Frustration

I've battled my privacy fence ever since it was built in November of 2010. So far, I've had to raise one section a couple of inches to help water run off and one crooked post was also replaced. The thing was so poorly built from the beginning that I get nervous every time the wind picks up. I will probably be lucky to get five years out of the thing before it has to be completely torn down and replaced. I'm dreading that day.

The gate has now been rebuilt three time due to sagging and warping. In its latest incarnation, I replaced both posts on each side of the gate because the old ones weren't level and the one on the hinge side leaned. I discovered that one only had 25 or so pounds of cement holding it in place. This third gate is reinforced with metal braces on all the joints as well as wood glue. I have four hinges holding it to the post and the posts around the door are braced with 2x4 boards making a rather sturdy frame. I'll probably add some cross braces later, but everything seems okay for now.