Already got about 3 topics about this. In a nut shell: you cant get the stats to work on any page other than the homepage, so unless you want to piddle about creating sidebars manually for every page - don't bother.
The online/staff stats - they only work on the homepage. Try to use them in the sidebar anywhere else and you get null results and errors in the header.
Basically it just means you have to have a different set of sidebars for the homepage and everywhere else. Still bummed that there is no 'if we're on this page show this, otherwise don't' option in templates like vB had It would allow 1 single template for all sidebars, with an <xen:if> around the bits that only work on the homepage.