When you log in on main forum page and navigate to other forum categories and you’ll see on top right asking you to log in again just press F5. Repeat it every time that happens and you should be ok.
Now to your question. Line height of 1.2 at body level is pretty small. 1.5 or higher is preferable. What do you mean by having double spacing in your table cell text? That 1.2 line height will cascade to every other element so it will be applied to your TD text also.