Perhaps someone can explain to me what is going on. I seem to be having extreme difficulty with posts involving LATex code. I am not LaTex expert, but this is ridiculous. There appears to be no resemblance between the Latex code that I enter and what appears when I attempt to preview the post. For instance, I prepare code to produce an integral, and that code is right before my eyes in the composition pane. Then I click "preview" and what I see is some algebraic sum from a thread that I particpated in yesterday. Or I make a mistake and change the code, and when I click "preview" the old, incorrect graphics, appears. To make matters worse, if I give up and just hit "enter", what appears in the thread is neither what I saw in the preview nor what is reflected by the Tex code. I there some sort of memory or cookie that I need to clear? Logging out (including shutting down my computer) and coming back does not seem to correct the problem. It is rather like the machine is haunted. I am becoming fond of pencil and paper.