Just a quick question... I haven't been able to figure out a way to preview my posts before I post them. Is there a way to check my LaTeX code on site before I actually post?
The MathJax resource is not loaded if the page does not have any ##\LaTeX##. When you are creating a new thread, as @Orodruin has said above, you need to refresh the page once to load the resource, and thereafter the preview will render the ##\LaTeX##. Before refreshing the page, however, make sure you copy everything you have written. There is a bug that renders some of the ##\LaTeX## in the edit window itself after you refresh the page, and then if you click the Preview button, everything will be garbled.