I might not have done a great job of explaining the differences and similarities of trials and temptations.  I think James is focusing on desires when he uses the same word for both.  The main difference is the desire behind the trial or temptation.  God’s desire for all of his trials is for us to grow not to be tempted away from him.  So it this way we can say that God tries us but does not tempt us.  His desire is for the trials to draw us closer to him not away through temptation.  Our desire is what changes a trial into a temptation.  Temptations come when we see trials and uses those trials to lead us away from God.  Our evil desires turn trials into temptation.  Hopefully that clears things up a bit more.