Thanks michael-
I'm not sure what you mean by 'manually' - I'm using whatever the thing is that took the place of Fantastico (how's that for a techie explanation?). With the old CP when I clicked to download SMF from Fantastico, a box popped up and all I had to do was put in /forum and the correct directory (abc.com/forum) magically appeared in the file manager.
Now I get 2 choices: root directory or a blank box. If I click 'root directory' it downloads, but I can't find it. If I type in any combination of http or ftp urls in the blank box it says 'invalid directory (or something like that) and won't download.
I'll go back and try again with your folder suggestion. Thanks again.