[NTG-context] Too many open files

Hi, with the actual minimals and luatex on Mac OSX I get "pdfError: Couldn't open file <image file name> Too many open files" and then fatal error 70. With an older installation everything is ok, minimals on Windows are ok, too. The document has about 700 figures. En detail: Working: OSX: context 2010.10.14 13:14; luatex (64) beta-0.63.0-2010091123 Working: Win XP: context 2011.01.24 10:00; luatex (32) beta-0.65.0-2010121421 Not working: OSX: 2011.01.24 10:00; luatex (64/32) beta-0.65.0-2010121316 Is this a known problem? Thanks for any help. Kind regards Thomas