Environment vars (JAVA_HOME) not working on Debian 4

Hello List,

I'm having a wired problem right now and I need some help.

I'm not able to set the JAVA_HOME variable

# export JAVA_HOME=/opt/jdk1.6.0_07
# echo $JAVA_HOME
/opt/jdk1.6.0_07
# sudo /opt/apache-tomcat-7.0.23/bin/startup.sh
Neither the JAVA_HOME nor the JRE_HOME environment variable is defined
At least one of these environment variable is needed to run this program

The variable looks like it is set but later the tomcat script is not able
to detect.
I can show more information if needed, just tell me what :)

Thank you in advance.
Oscar