Sorry to bump this, but it's driving me mad. Probably because I am dim.
Being more specific, when defining dashlets for a custom site preset in presets.xml, you have to define a path to the dashlet. The default ones all appear to be in /components/dashlets.
However, when I install an addon dashlet, such as the site blog dashlet by dropping a .jar into tomcat/shared/lib it doesn't appear to deploy the dashlet into components/dashlets.
I am probably doing something really stupid, or missing the point of something completely, but does anyone know what it is?