Hi Fons - your guess was correct - Charles was missing `-fno-rtti' ...
As for your comment - it is true only under certain assumptions. In particular,
if the library is supposed to be used *outside* ROOT interactive session (yes,
this also happens) it is better to link it against ROOT libs. In general it
is a good practice to link shared libs with *all* the references resolved,
unfortunately it is not always possible (you definitely don't want to
resolve references from the static libraries).
-Pasha