Hi,
I got the same hang where I have to use the break key to get my shell back even if I'm using TEST::MORE like you mentioned. Here is how my script looks and what was logged during my tests:

/tmp/DBI-1.633>
/tmp/DBI-1.633>cat t/00simple_test.t
#!perl -w

use strict;

my $LOG;
my $LOG_FILE = './test_log';
open ($LOG,  '>>', $LOG_FILE )
                or die "Could not open the file $LOG_FILE!\n$!\n";

print $LOG "###################################\n";
print $LOG "Step_00:   (START of script:$0)\n";
print      "ok 1 - running the test $0\n";
print $LOG "Step_01:\n";
1;
print $LOG "Step_02:\n";

use Test::More qw( no_plan );
print $LOG "Step_03:\n";
ok(1);
print $LOG "Step_04:   (END of scrit:$0)\n";
/tmp/DBI-1.633>
/tmp/DBI-1.633>rm test_log
/tmp/DBI-1.633>
/tmp/DBI-1.633>
/tmp/DBI-1.633>perl t/00simple_test.t
ok 1 - running the test t/00simple_test.t
ok 1
1..1
/tmp/DBI-1.633>cat test_log
###################################
Step_00:   (START of script:t/00simple_test.t)
Step_01:
Step_02:
Step_03:
Step_04:   (END of scrit:t/00simple_test.t)
/tmp/DBI-1.633>prove -v t/00simple_test.t
t/00simple_test.t .. /tmp/DBI-1.633>cat test_log
###################################
Step_00:   (START of script:t/00simple_test.t)
Step_01:
Step_02:
Step_03:
Step_04:   (END of scrit:t/00simple_test.t)
###################################
Step_00:   (START of script:t/00simple_test.t)
Step_01:
Step_02:
Step_03:
Step_04:   (END of scrit:t/00simple_test.t)
/tmp/DBI-1.633>
/tmp/DBI-1.633>
/tmp/DBI-1.633>make test t/00simple_test.t
PERL_DL_NONLAZY=1 "/usr/bin/perl" "-MExtUtils::Command::MM" "-MTest::H
+arness" "-e" "undef *Test::Harness::Switches; test_harness(0, 'blib/l
+ib', 'blib/arch')" t/*.t
t/00simple_test.t ............... make: *** [test_dynamic] Interrupt
/tmp/DBI-1.633>
/tmp/DBI-1.633>
/tmp/DBI-1.633>cat tes_log
cat: tes_log: No such file or directory
/tmp/DBI-1.633>cat test_log
###################################
Step_00:   (START of script:t/00simple_test.t)
Step_01:
Step_02:
Step_03:
Step_04:   (END of scrit:t/00simple_test.t)
###################################
Step_00:   (START of script:t/00simple_test.t)
Step_01:
Step_02:
Step_03:
Step_04:   (END of scrit:t/00simple_test.t)
###################################
Step_00:   (START of script:t/00simple_test.t)
Step_01:
Step_02:
Step_03:
Step_04:   (END of scrit:t/00simple_test.t)
/tmp/DBI-1.633>
[download]

So it looks that it's not a aproblem with the script it is the procedured how the script will be called and how the control will be given back to the calling module.
wollik