This is an odd situation and I'm just about at wit's end...

On HP/UX we have some perl scripts to communicate via LWP::UserAgent.

Some users can run the script, no problem; others get the following error:

Socket object version 1.94 does not match bootstrap parameter 2.006 at
+ /opt/perl514/lib/5.14.2/PA-RISC2.0-thread-multi/DynaLoader.pm line 2
+13.
Compilation failed in require at /opt/perl514/lib/5.14.2/PA-RISC2.0-th
+read-multi/IO/Socket.pm line 12.
BEGIN failed--compilation aborted at /opt/perl514/lib/5.14.2/PA-RISC2.
+0-thread-multi/IO/Socket.pm line 12.
[download]

Where it dies is on "require IO::Socket" (or anything that pulls in "Socket.pm").

In trying to debug this, we've dumped lots of environment variables and @INC and %INC at various stages. All users show they're using /opt/perl514/lib/... for loading libraries.

So for debugging output we generated a listing of loaded modules based on keys %INC:

foreach my $file ( sort keys %INC ) {
   my $mod = "$file";
   next unless $mod =~ s/[.]pm$//;
   $mod =~ s{/}{::}g;
   my $ver = eval('$' . $mod . '::VERSION or "[unknown]"');
   push @output, [ $mod, $ver ];
}
...
[download]

Users who CAN run the script have these modules loaded right before "require IO::Socket":

AutoLoader                       5.71
Carp                             1.20
Compress::Raw::Zlib              2.045
Config                           [unknown]
Crypt::SSLeay                    0.58
Crypt::SSLeay::CTX               [unknown]
Crypt::SSLeay::MainContext       [unknown]
Crypt::SSLeay::X509              [unknown]
Errno                            1.13
Exporter                         5.64_03
Exporter::Heavy                  5.64_03
Fcntl                            1.11
File::Glob                       1.13
File::GlobMapper                 1.000
File::Spec                       3.33
File::Spec::Unix                 3.33
Getopt::Std                      1.06
HTTP::Config                     5.815
HTTP::Date                       5.831
HTTP::Headers                    5.827
HTTP::Message                    5.834
HTTP::Request                    5.827
HTTP::Response                   5.824
HTTP::Status                     5.817
IO                               1.25_04
IO::Compress::Base::Common       2.045
IO::Compress::Gzip::Constants    2.045
IO::Compress::Zlib::Extra        2.045
IO::File                         1.15
IO::Handle                       1.31
IO::Seekable                     1.1
IO::Socket                       1.32
IO::Socket::INET                 1.31
IO::Socket::UNIX                 1.23
IO::Uncompress::Adapter::Inflate 2.045
IO::Uncompress::Base             2.046
IO::Uncompress::Gunzip           2.045
IO::Uncompress::RawInflate       2.045
LWP                              5.834
LWP::MemberMixin                 [unknown]
LWP::Protocol                    5.829
LWP::Protocol::http              [unknown]
LWP::Protocol::https             [unknown]
LWP::UserAgent                   5.834
List::Util                       1.23
MIME::Base64                     3.13
Net::HTTP                        5.834
Net::HTTP::Methods               5.834
Net::HTTPS                       5.819
Net::SSL                         2.85
Scalar::Util                     1.23
SelectSaver                      1.02
Socket                           2.006
Storable                         2.30
Symbol                           1.07
Time::Local                      1.2000
URI                              1.59
URI::Escape                      3.31
URI::_generic                    [unknown]
URI::_idna                       [unknown]
URI::_punycode                   0.04
URI::_query                      [unknown]
URI::_server                     [unknown]
URI::http                        [unknown]
URI::https                       [unknown]
XSLoader                         0.13
bytes                            1.04
constant                         1.21
feature                          1.20
integer                          1.00
overload                         1.13
strict                           1.04
utf8                             1.09
vars                             1.02
warnings                         1.12
warnings::register               1.02
[download]

By contrast, the users who CANNOT run the script, have these modules loaded instead -- e.g. DynaLoader instead of AutoLoader?

Carp                 1.20
Config               [unknown]
DynaLoader           1.13
Errno                1.13
Exporter             5.64_03
Exporter::Heavy      5.64_03
Fcntl                1.11
Getopt::Std          1.06
HTTP::Config         5.815
HTTP::Date           5.831
HTTP::Headers        5.827
HTTP::Message        5.834
HTTP::Request        5.827
HTTP::Response       5.824
HTTP::Status         5.817
IO                   1.25_04
IO::Handle           1.31
IO::Socket           [unknown]
IO::Socket::INET     [unknown]
LWP                  5.834
LWP::MemberMixin     [unknown]
LWP::Protocol        5.829
LWP::Protocol::http  [unknown]
LWP::Protocol::https [unknown]
LWP::UserAgent       5.834
MIME::Base64         3.13
Net::HTTP            5.834
SelectSaver          1.02
Socket               2.006
Storable             2.30
Symbol               1.07
Time::Local          1.2000
URI                  1.59
URI::Escape          3.31
URI::_generic        [unknown]
URI::_idna           [unknown]
URI::_punycode       0.04
URI::_query          [unknown]
URI::_server         [unknown]
URI::http            [unknown]
URI::https           [unknown]
XSLoader             0.13
constant             1.21
integer              1.00
overload             1.13
strict               1.04
vars                 1.02
warnings             1.12
warnings::register   1.02
[download]

All module-paths (from values %INC) are /opt/perl514/lib/...

Suggestions?