Actually, I'm having the same problem. I've spent the last three hours searching the forums and fiddling with my file and I also can not get any mods to show up in my mod preferences screen. Once I was able to get a map to show up, but when I upgraded to 3.23b that went away, too.
Is this a macintosh thing?
I've read that maybe I need to open up the files in a particular text editor and save them from it before the application will recognize them. Can anyone confirm this? If so, what text editor should I use?
Thanks.