Adding plugin deletes InDesign (workspace) settings

Hi,

we discovered the following strange behaviour: By adding a plugin to the InDesign plugin folder (via Drag&Drop) several user settings of InDesign will be deleted. For example: The list of recently opend documents, the preview checkbox in paragraph styles…

This happens with the plugin we're developing at the moment, but it also happens with compiled samples from the SDK, so we are really unsure where to look for the bug.

We're working with InDesign CS6  on a Mac.

Does anyone know what might going wrong?

Thanks!