Check the vmware-install.pl - You have to find following line:
if ( direct_command("cat /etc/*-release | grep -i ubuntu") || direct_command("cat /proc/version | grep -i ubuntu") ) {
change it to
if ( direct_command("cat /etc/*-release | grep -i ubuntu") || direct_command("cat /proc/version | grep -i debian") ) {
Besides you'll need to install following Debian-packages if you want to use check_esx3.pl
- libconvert-units-perl (with apt-get the dependencies should be installed too: libclass-accessor-perl, libconfig-tiny-perl)
- libmath-calc-units-perl (for Lenny from backports-repository: http://packages.debian.org/lenny-backports/all/libmath-calc-units-perl/download)
- libnagios-plugin-perl_0.35-1_all.deb (from the Sid-repository: http://packages.debian.org/sid/all/libnagios-plugin-perl/download)
- libxml-perl
- libclass-methodmaker-perl
- libnet-ssleay-perl
- libcrypt-ssleay-perl
For the installation of the VMware Perl SDK I also set
LD_LIBRARY_PATH=/usr/lib
LIBDIR=/usr/lib
I forgot to unset them before my last installation attempt and so I don't know yet if those variables are really needed 
- I tried lot's of stuff until I found the "ubuntu"-line**
Works like a charm on my Debian 5.0 atm.
** EDIT
I had again a quick look at my edited vmware-install.pl - and yes the two variables seem to be used for the installation - but i edited the line from
my $libdir = db_get_answer('LIBDIR') . '/lib';
to
my $libdir = db_get_answer('LIBDIR');
I edited this file because otherwise the script would have a look at the /usr/lib/lib