is there a Java VM for NV+

I have the same problem, but the suggested solution doen´t work. I'm trying this on my ReadyNas NVX Pioneer. My sources.list looks like this:

deb http://www.readynas.com/packages 4.2.13/
deb http://archive.debian.org/debian etch main
deb http://us.archive.ubuntu.com/ubuntu dapper main restricted
deb http://us.archive.ubuntu.com/ubuntu dapper universe multiverse
deb http://archive.canonical.com/ lucid partner

When i run apt-get update the following errors are shown.

[.......]
Hit http://www.readynas.com 4.2.13/ Packages
Fetched 43.4kB in 1s (29.9kB/s)
Reading package lists... Done
W: GPG error: http://archive.canonical.com lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
W: GPG error: http://us.archive.ubuntu.com dapper Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
W: You may want to run apt-get update to correct these problems

When I try to install java, apt-get install sun-java6-jdk, I get errors about dependicies.

NAS:/# apt-get install sun-java6-jre
Reading package lists... Done
Building dependency tree... Done
You might want to run `apt-get -f install' to correct these:
The following packages have unmet dependencies:
  libsigc++-2.0-dev: Depends: pkg-config but it is not going to be installed
                     Depends: libstdc++-dev
  sun-java6-jre: Depends: java-common (>= 0.24) but it is not going to be installed
                 Depends: sun-java6-bin (>= 6.20dlj-1ubuntu3) but it is not going to be installed or
                          ia32-sun-java6-bin (>= 6.20dlj-1ubuntu3) but it is not installable
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

Does anyone have an idea to resolve the Public Key errors?
Thansk in advance.