Newer suspension setup...reocurring ujoint issues

I upgraded my suspension last fall and replaced the u-joints at the same time. Since nissan uses crappy u-joints they needed to be replaced. I added new leaf spring kit in rear and radflows in front. The u-joints I added were greaseable. Did it every oil change or so which is more than enough for greasing. Now 7 months later one of the replaced u-joints is bad. Would the setup of the suspension make or increase the life of the u-joint to go bad this quickly. I am replacing them with warranteed u-joints from Autozone. Is there anything I can do to help the wear on them? It is the rear driveshaft also. Thanks.