Okay, like I said, I'm new at Joomla.
Tried to install the extension and it told me "no dice, it's already installed".
So, I uninstalled it, then installed it. That caused all my menus to become disabled and revert back to type mod_mainmenu. I cannot see any way to change them back to mod_sbd_rollmenu.
The install then proceeded to create a new directory under modules called mod_dbd_rollmenu_new. And if I were to try and recreate the menus from scratch when I choose New I see 2 radio buttons for SBD Rollmenu. This seems like a lot of work and now I'm deathly afraid of what will happen when I need to upgrade any extensions in the future.
Luckily I just uploaded everything to the web and did this update on my localhost dev site. I'm going to revert everything, but I want to help with your testing if I can. I thought I would just have to install the extension you sent me, then copy back in my CSS files?