Update 25th Aug. 2011: the bug discussed here is still present. I recommend all WordPress Multi Site users install the Proper Network Activation plugin that is available here at the WordPress site. I noticed a compatibility bug between WordPress 3 Multi Site and Greg's High Performance SEO so reported the issue to Greg who very quickly took a look at it. It turns out that WordPress Multi Site does not like it when plugins are Network Activated. So, as a warning to all WordPress Multi Site users, do not Network Activate plugins. Not yet, anyway. To paraphrase Greg's explanation: When a … [Read more...]