I was not able to reproduce your problem using Perl 5.8.7 on darwin os version 7.9.0 (Mac OS X 10.4).

[HTML-Tagset-3.10] 511 $ perl Makefile.PL;make
Checking if your kit is complete...
Looks good
Writing Makefile for HTML::Tagset
cp Tagset.pm blib/lib/HTML/Tagset.pm
Manifying blib/man3/HTML::Tagset.3
[HTML-Tagset-3.10] 512 $ make test
PERL_DL_NONLAZY=1 /usr/local/bin/perl "-MExtUtils::Command::MM" "-e" "
+test_harness(0, 'blib/lib', 'blib/arch')" t/*.t
t/00_about_verbose....ok                                              
+       
t/01_old_junk.........ok                                              
+       
t/pod.................ok                                              
+       
All tests successful.
Files=3, Tests=4,  1 wallclock secs ( 0.25 cusr +  0.12 csys =  0.37 C
+PU)

[HTML-Tagset-3.10] 515 $ prove -vb t/pod.t
t/pod....1..1
ok 1 - blib/lib/HTML/Tagset.pm
ok
All tests successful.
Files=1, Tests=1,  0 wallclock secs ( 0.18 cusr +  0.05 csys =  0.23 C
+PU)

[HTML-Tagset-3.10] 518 $ perl -T -Iblib/lib t/pod.t 
1..1
ok 1 - blib/lib/HTML/Tagset.pm
[download]

Note that t/pod.t is simply an instance of Test::Pod::all_pod_files_ok() which some CPAN authors (including Andy, but not me!) like to throw into their test suites.

use Test::More;
eval "use Test::Pod 1.14";
plan skip_all => "Test::Pod 1.14 required for testing POD" if $@;
all_pod_files_ok();
[download]

If, as you say, this problem occurs with many CPAN modules, can you determine whether it is this function which is causing the hang? If so, then it may be something specific to the interaction of Test::Pod and Test::Harness on cygwin.