It's because you need to enable the Joomla 1.5 Legacy Plugin, as this plugin is not 1.5 native.
I've made a topic asking the developer if and when he will make this plugin J1.5 native.
Oops, i've found the answer:
"New version compatible with J 1.5.X is currently available for doc subscribers - and there is a detailed document in the package also."
Post edited by: PCAnalyzer, at: 2009/12/23 15:57