[NTG-context] TeX-MP interaction in mkii and mkiv

Hi, I cannot understand why mkii and mkiv give different output in the attached example modified from Thomas's presentation module. The output of MKII is correct. In MKIV, the first picture (Left) is not correct, and I cannot understand why is this the case. I am using the latest minimals and the latest svn luatex. Thanks, Aditya