OK, sure. Thanks for the response!
FYI - I did have another plugin for custom post types, but I had not used it before I saw yours. Thinking that might be the culprit - I have deleted it. It was Custom Post Type UI by WebDevStudios. I have also removed and re-installed Suffusion.
Using Suffusion's Custom Types, I created a post type called ShowMe Videos. Now that I understand I can see where I need to enter 'Create New Video' in the place where 'ShowMe Video' is in this screenshot:

So, I go back into Custom Posts and I see the Post Type there:

When I click edit, this is what I get:

Same thing happens with Custom
Taxonomies. I can see 'Subject' there, but when I edit - it acts like I'm entering a new one. I can actually make a 'new' one with the exact same name 'Subject' and re-enter all the options. But, I can't see what the current options are.
Follow-up: thinking maybe the space in my post type (ShowMe Video) was the culprit, I just added a new Post Type named geek-video. When I saved, geek-video was on the list and ShowMe Video was gone. Trying to edit geek-video still gave me a blank, new screen.