"deep recursion / out of memory" error

Hi CPAN experts,

I've been using perl and CPAN on my web server for years.  My web  
hosting provider is a "parental" one who periodically does their own  
updates on the various software items.  (This may or may not relate to  
my problem.)

Today I decided to upgrade the various downloaded perl modules on the  
server, being particularly interested in updating SpamAssassin.  My  
first attempt failed because I forgot to include "sudo" before the  
perl command, like this:
---------------------------------------------------------------------
animalhead:~ $ perl -MCPAN -e "shell"
CPAN: File::HomeDir loaded ok (v0.64)

cpan shell -- CPAN exploration and modules installation (v1.9102)
ReadLine support enabled

cpan[1]> help
<help output snipped>

cpan[2]> upgrade CPAN.pm
CPAN: Storable loaded ok (v2.16)
Going to read /home/mackenna/.cpan/Metadata
   Database was generated on Wed, 11 Jul 2007 22:51:14 GMT
CPAN: LWP::UserAgent loaded ok (v2.033)
CPAN: Time::HiRes loaded ok (v1.9707)
Fetching with LWP:
   http://www.perl.org/CPAN/authors/01mailrc.txt.gz
CPAN: YAML loaded ok (v0.62)
Could not open '/home/mackenna/.cpan/FTPstats.yml': Permission  
deniedGoing to read /home/mackenna/.cpan/sources/authors/01mailrc.txt.gz
Lockfile removed.
Undefined subroutine &Compress::Zlib::gzopen called at /usr/local/lib/ 
perl5/5.8.8/CPAN/Tarzip.pm line 103.
---------------------------------------------------------------------

The second attempt went like this:

---------------------------------------------------------------------
animalhead:~ $ sudo perl -MCPAN -e "shell"
Password:
CPAN: File::HomeDir loaded ok (v0.64)

cpan shell -- CPAN exploration and modules installation (v1.9102)
ReadLine support enabled

cpan[1]> upgrade CPAN.pm
CPAN: Storable loaded ok (v2.16)
Going to read /home/mackenna/.cpan/Metadata
   Database was generated on Wed, 11 Jul 2007 22:51:14 GMT
Going to read /home/mackenna/.cpan/sources/authors/01mailrc.txt.gz
CPAN: Compress::Zlib loaded ok (v2.004)
Deep recursion on subroutine "Compress::Raw::Zlib::AUTOLOAD" at /usr/ 
local/lib/perl5/site_perl/5.8.7/i386-freebsd/Compress/Raw/Zlib.pm line  
71.
Out of memory!
Lockfile removed.
animalhead:~
----------------------------------------------------------------------

Since then, any CPAN command, even just "clean", ends up with a  
similar "deep recursion / out of memory" error.

How can I bypass this error while minimizing loss of downloaded modules?

Thanks,
Craig MacKenna