EDIT: This is resolved, but I don't know how or why this worked.
I simply uploaded another theme and once again clicked on the "Presentation" link in the admin panel. Voila, they were all there again.
I had refreshed the page several times, so that was not the issue. I do not know why uploading another theme appears to have fixed the issue.
Baffled, but glad that it's working again..
I have upgraded to WordPress v2.2, and after the upgrade my list of "Available Themes" is empty.
Here is a screen shot of what I'm talking about:
As you can see, the currently running theme IS listed, but everything under "Available Themes" is now gone.
I have not changed anything in the themes.
I have not changed anything with the directories of the themes.
The themes are NOT listed inside of sub-directories (ala wp-themes/title/title/)
I have only upgraded to v2.2, and now it appears that WP suddenly does not see the other themes.
This has occurred on two different blogs, both of which the only change has been an upgrade to v2.2
I would appreciate any assistance with this, and thank those in advance who wish to share their experience. :)