CPAN using wrong directory?

[Fatted Shmatted]

I'm on Solaris 8 and I have 3 versions of perl available to my system.
The standard (/usr/bin/perl version 5.005) version that comes with
Solaris, a version on a mounted partition (/net/jupiter/... version
5.6.1) and my own local copy in (/usr/local/bin version 5.8.7).
I'm trying to install some modules using CPAN:

/usr/local/bin/perl -MCPAN -e shell

and then do a

install Bundle::CPAN

CPAN: Storable loaded ok
Going to read /opt/.cpan/sources/authors/01mailrc.txt.gz
Going to read /opt/.cpan/sources/modules/02packages.details.txt.gz
Database was generated on Mon, 06 Feb 2006 06:47:45 GMT
HTTP:ate not available

There's a new CPAN.pm version (v1.83) available!
[Current version is v1.59_54]
You might want to try
install Bundle::CPAN
reload cpan
without quitting the current session. It should be a seamless upgrade
while we are running...

Going to read /opt/.cpan/sources/modules/03modlist.data.gz
Could not pipe[/bin/gzip --decompress --stdout
/opt/.cpan/sources/modules/03modlist.data.gz |]: Not enough space at
/net/jupiter/usr/local/lib/perl5/5.6.1/CPAN.pm line 5580.

Any idea why its trying to use the CPAN module from the 5.6.1 version?