[NTG-context] Problem with Xetex

Probably I am the most troubled, unsuccessful beginner in this list (it's my <i>fado</i>), anyway: I have two installations of context: one in ~/texmf; another in ~/context to which I switch typing . ~/context/tex/setuptex ~/context/tex. The first one has a problem with 8bit output (\enableregiem[utf8]: it says in the log file: possible problem with 8bit output. Xetex hangs on with: kpathsea mktextfm lmroman... The second installation has another problem with xetex: "could not open config file dvipdfmx.cfg"