[NTG-context] No bonds visibel with ppchtex

Hi there, I try to write some structures with ppchtex, but I found that the bonds will not beeing drawn. Simple examble: \usemodule[chemic, units, pictex] \mainlanguage[de] \language[de] \enableregime[il1] \setupencoding[default=texnansi] \setuppapersize[A4] \starttext \startchemical \chemical[ONE,SB1,SB4,SB2,SB7,Z01247][C,H,H,H,H] \stopchemical \stoptext This results in only the symbols. but no bonds. Any suggestions? Thank you, Kai