Hello Sebastien,
try setting your JAVA_HOME to:
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
I know the symlinked /System/Library/Frameworks/... should work but I tried both versions and only one of them did. Which output does:
/usr/libexec/java_home -v1.6
give you?
Hopefully helps.