My site category selection was working but at some point the category selection on the blog creation page stopped woking. I have tweaked the settings and now the dropdown on site category selection is not selectable. I have dectivated, deleted, and re-installed the plugin but it looks like the old categorys are still active. It looks to me like the database entrys are keept when the plugin is deleted. Could you guide me om how to delete old database entrys, and install the plugin so it will work as a fresh plugin installation.