Quote Originally Posted by WayTags1 View Post
A fresh install to a subdirectory produced similar results...
- I am unable to access the admin part of the store; however
- I am able to complete checkout -- all secure (https)

Any Thoughts?
If you're able to login to the admin and you're able to use the storefront and do checkout properly with ssl (which all sounds very normal), then if your *other* setup doesn't do that, you've got a problem in one or more of your customizations.

So, you'll need to find that problem.

This is the concept you'll likely need to follow:
http://www.zen-cart.com/wiki/index.p...Obscure_Issues

Make and keep backups while you're at it.
Sometimes having a backup from 2 days ago, after discovering something's busted, can be a lifesaver.