[NTG-context] Coupled register errors!

Hi, A few years ago I created a screen document met menus and coupled registers, and it just worked fine. A fresh compilation of this document throws several 'undefined control sequence' errors; so I wonder what has happened to this feature? Are commands like \defineregister, \setupregister and \couple(d)register still valid ConTeXt commands? Currently I use ConTeXt ver: 2011.03.30 11:21 MKIV fmt: 2011.3.30 int: english/english. Regards, Gerard Verhaag