[NTG-context] Standard ligatures in ec encoding

Hi all, I have installed the URW fonts with texfont --batch --encoding=ec type-tmf.dat The \setupbodyfont[pos,10pt] works well, but there is no f-ligatures in the output. The fi and fl are in the character table (in ec-urw-times.tex the \ShowFont shows both), but \showligatures doesn't show these. What is wrong? Greetings Bence Nagy