I found the solution for this bug!
on my windows, an old java updates put java.exe, javaw.exe in windows
\system32 folder which is the first in the path. I deleted them and
checked my path variable.
I set to a %JAVA_HOME%\bin and JAVA_HOME points to a jdk/jre where lib
\audio\
soundbank.gm file exists. If this file doesn't exist (I've
tested with a jre without it) I get the exception.
I can now say that abc4j is compatible with java 6 :-) (but in my
eclipse settings, I set the compiler to be 1.4 compatible for people
using old jre).