[NTG-context] Conflict between blackboard bold font and enumerations

Hi, I've got a problem with "\blackboard". When I use it in the title of an enumeration (title=yes in setupenumerations), I get this error during compilation: ! Incomplete \iffalse; all text was ignored after line x. <inserted text> \fi For instance: \starttext \defineenumeration[hello] \setupenumerations[hello][title=yes] \starthello{$\blackboard{ABCD}$} \stophello \stoptext Yet if I replace "\blackboard{ABCD}" with \reals (or \naturalnumbers, or \integers etc.), it works fine. What's wrong? Thanks. Géry