In xp Pro sp3. I have the fonts group folder with a few subfolders and fonts inside. I have reinstalled windows and the first time I ran MainType I could see the folders in the groups tab for 1-2 seconds. Now it is disappeared, if I create a new folder I can see it in windows explorer but not anything inside MainType. I have tried changing the font group folder in options but it makes no difference.
Maybe the groups list is hidden. You can restore the default layout by this key combination: CTRL-1. You can also choose another layout by selecting Layout from the View menu. Do let us know your results.
Restoring the default layout solved the problem. All the folders and fonts show up in the group pane now. Thank you very much!