Uninstall and reinstall it. You were using it before, were you not? Follow the instructions here, downloading the executable version: http://sites.google.com/site/oblivionpoinfo/prep/obmm.
Oh, do not uninstall just yet!! I'll update this in a sec with some instructions that may save you a few hours.
Edit: First, try installing the executable on top of your current install, after following the directions I am about to post.
Edit: Look at the import/export options. You should export your active OMOD list. It is kind of like using the "saveini" command to force the game to save changes to the Oblivion.ini file when you no it is threatening CTDs. I do not think that any of the other functions are useful. Just export the list to your desk or something.