[NTG-context] xetext-pdftex differences

Hi, as there are some on this list working/playing with xetex/context: Where do I go when I experience differences between context/pdftext and context/xetex? For example with context/xetex I get ... ! Undefined control sequence. \stopframedtext ->\dostopframedtext ... and I do get "SS" instead of eszett ("ß") with the following: \usetypescriptfile[type-gyr] \usetypescript[times][ec] \mainlanguage[de] \enableregime[utf] \setupbodyfont[times,9pt] Hello Thermes! 1234567890 üööäß Whom to tell this? Steffen P.S. Besides these details it is amazing how smooth ConTeXt files run with XeTeX!!