Thanks guys. Anyway,

[***@******//~] cat gdtest.pl
use lib '/home/***/lib/perl5/site_perl/i386-linux';
use GD;

print "$GD::VERSION\n";
[***@******//~] perl gdtest.pl
2.06
[download]

Seems to have yielded the correct version number. I tried using lib '/home/anonymonk/lib/perl5/site_perl' but the i386-linux directory where GD was installed wasn't being included. Anyway, that seems to have fixed it.