Hi,
I actually fixed the problem by importing most of the tooltip css from the protostar template into my custom template. That seems to have fix the positioning problem for my other tooltips as well, e.g. my registration form.
But now I have another problem. The tooltip for the vote system (only the vote system as far as I can tell) just show some default system tooltip layout which does not support any html. See my screenshot *image my mouse cursor is over the "total vote count" span*. Any idea why?
As always, thanks for your reply.