Hi Tom
To check what version you have of plugins and question types go to Site admin > Plugins > Plugin Overview
The latest Totara 2.2.14 has a later version of qtype-multichoice 20111002700 (if I am reading my dates right) so theoretically should work if the plugin is upwardly compatible. Seeing the some or nothing it is a non standard plugin Totara doesn't support this and are not familiar with this plugin. Any changes to the code would need to go to the contributor of this plugin or maybe a Totara partner who is familiar with this.
Craig