I was running into this same issue recently. The exception to my situation is that I’m running a local installation of WordPress using MAMP and was unable to see the changes that I had made to a template after copy/pasting the source files into a newly created theme directory. My first inclination was that it was a permissions issue, but after verifying that all the files had read/write privileges, I was stumped. After reviewing both sets of files and going back and forth between Dreamweaver and my WP-Admin folder, I discovered that in order for WP to “see” your theme, you must have the description information in your CSS file be different than any other theme in the themes folder. Because I just duplicated it and essentially renamed the directory, it wasn’t able to parse it as a new theme. The solution for me was to go into the styles.css file and supply unique descriptive info. Here’s what you need to edit:
/*
Theme Name:
Theme URI:
Description:
Version:
Author:
Author URI:
*/
In your case, you may just need to insure that your CSS file contains this information. WordPress apparently uses this information to define your theme in the admin area. Without it (or having is as a duplicate like I did) causes it not to be able to identify your theme.
Give it a shot and let me know how it works out. It worked for me once I realized what was going on.
– Anthony