White page After Insert Image On WP 3.0.x and Atahualpa 3.6.x

I'm getting a persistent white page after using the Media Manager to upload and/or insert an image file into a post. This started a week or so ago after upgrading WP 3.0.4 > 3.0.5 and Athualpa 3.6.1 > 3.6.4.

The title of the image is always carrying the red asterisk for invalid, but it is allowing the Insert Image command.

The behaviour is the same with all plugins disabled and while adding them in one at a time or in small groups.

Also, while in the Admin screens, I'm getting occasional site page displays with a "No Content Found" message, although refreshing usually returns me to the appropriate Admin screen.

Any thoughts, hunches, or wild ass guesses?

TIA,
Art