  The two papers in the title contain some equations that are not complete. The
missing terms, which are of topological origin, were recently unveiled by Bjorn
Gustafsson. In this note we present the equations of Gustafsson in the case of
a single vortex in a compact boundaryless surface, and show that many
conclusions we have reached with the incomplete equations remain valid. It
seems that the the extra-terms in Gustafsson's equations can be explicitly
written in terms of elementary functions only for the two-torus, and this is
done at the end of this note.
