since my user compilers seem to work ...
i did a full rebuild to rev 3474 and now it works with a "by hand" edited *.conf file,
starting from a new default.conf, and importing the custom compiler section ...
don't know exactly what happened, but somehow the migration from my previous *.conf file
into CB rev 3467 didn't work automatically.
anyhow, thanks for your assistance
brgds, --tiwag