On launch, if Apprunner doesn't find a plugins directory under bin it looks for the most recently used Communicator's plugins directory (i.e. a 4.x one) and does not handle some of them very well. Workaround:if you create an empty plugins directory under the bin directory you should be able to prevent this.
Or need a better way to handle load that is not needed.
Apparently there is some incompatibility with the way we're calling "new style" plugins. Specifically, the signature of the C entry points changed.
There is no way around this unless you install the new version of the OJI plugin: Go to http://warp/core/plugins/drops/oji/jre1_2_2-win-i.exe