I found a solution for all the issue I had listed above.
Trash the wp-admin and wp-includes folders in your WordPress site and replace with new, clean copies. Then dump cookies and cache from your browser. (I restarted my browser for good measure, though don’t think necessary).
That fixed all my issues (listed above) on both installs of WordPress 2.9.2.
Not sure what the issue was, but found this suggestion at <https://www.ads-software.com/support/topic/279132?replies=110> and it worked.
Remember to backup before doing anything and, if it works for you, backup again with the new folders in place.