Looks like I spoke a little too soon…
I noticed that Bad Behavior 2.0.13 had been updated by the plugin’s authors, and so attempted an automatic upgrade (part of the improvements with WP 2.5), and was greeted with
Downloading update from http://downloads.wordpress.org/plugin/bad-behavior.2.0.14.zip
Unpacking the update
Deactivating the plugin
Removing the old version of the plugin
Installing the latest version
Installation failed
Not exactly the end of the world, and once I realised that the core file ( bad-behavior-wordpress.php ) had been deleted during the process (normal behaviour), I didn’t worry about it no longer appearing in the list of plugins available for activation. I uploaded the file, and then overwrote the original associated updated bad-behavior directory, and proceeded to activate it with no problems.
So, assuming you take the time to read any messages during attempting an automatic upgrade of plugins, no harm is done 🙂
btw, this is the first plugin I’ve found that did not like the upgrade process…