First of all: Be very careful with “Add Meta Tags” plugin. I dedicated probably not too much time, but the thing is that looks to me that doesn’t create Dublin Core valid metadata (or at least is not detected by “Seo Quake” analysis).
Furthermore, it puts your description line into the body instead of inside metas. fortunately, I’ve made a backup and could restore hasslesly.
Does not having Dublin Core metadata damages my SEO? Definetely not. Does improve my rankings? At least looks like Google its indexing it.
If I find any useful plugin for this, Ill post it here.
[ edit ] Found “Dublin Core Metadata” Plugin, its simple and does not break anything. DC Metadata Still undetected by SEO Quake. Cant confirm by now.