[NTG-context] Metafun scaling problem

Hi Hans, hi all, I think, that recent context has a problem with scaling included pdf files. My minimal file: \startMPpage draw externalfigure "cow.pdf" ; \stopMPpage The resulting pdf is, as the original, 97x70.6 mm, all ok. If I try to scale to the original size, i get arithmetic overflow error. \startMPpage draw externalfigure "cow.pdf" xscaled 97mm yscaled 70.6mm ; \stopMPpage Whe i scale it down, the pdf gets really big. \startMPpage draw externalfigure "cow.pdf" xscaled 27.5mm yscaled 20mm ; \stopMPpage results in a pdf with width of 4.938,8 mm and height of 2.612,3 mm. I tested with recent context and luatex under windows 64 and linux-armhf. Greetings Lutz