Thanks Boris,
I still get the same failures ...

linux:/home/Plankton/mod_perl/mod_perl-1.99_13 # rm t/logs/error_log 
linux:/home/Plankton/mod_perl/mod_perl-1.99_13 # export APACHE_TEST_PO
+RT=44444
linux:/home/Plankton/mod_perl/mod_perl-1.99_13 # make test TEST_VERBOS
+E=1 TEST_FILES='t/apache/add_config.t'
cd "src/modules/perl" && make -f Makefile.modperl
make[1]: Entering directory `/home/Plankton/mod_perl/mod_perl-1.99_13/
+src/modules/perl'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/Plankton/mod_perl/mod_perl-1.99_13/s
+rc/modules/perl'
make[1]: Entering directory `/home/Plankton/mod_perl/mod_perl-1.99_13/
+Apache-Test'
    .
    .
    .
make[1]: Leaving directory `/home/Plankton/mod_perl/mod_perl-1.99_13/x
+s'
/usr/bin/perl -Iblib/arch/Apache2 -Iblib/lib/Apache2 \
t/TEST -clean
[warning] setting ulimit to allow core files
ulimit -c unlimited; /usr/bin/perl /home/Plankton/mod_perl/mod_perl-1.
+99_13/t/TEST -clean
APACHE_TEST_GROUP= APACHE_TEST_HTTPD= APACHE_TEST_PORT=44444 APACHE_TE
+ST_USER= APACHE_TEST_APXS= \
/usr/bin/perl -Iblib/arch/Apache2 -Iblib/lib/Apache2 \
t/TEST -bugreport -verbose=1 t/apache/add_config.t
[warning] setting ulimit to allow core files
ulimit -c unlimited; /usr/bin/perl /home/Plankton/mod_perl/mod_perl-1.
+99_13/t/TEST -bugreport -verbose=1 't/apache
/add_config.t'
[warning] root mode: changing the files ownership to 'nobody' (65534:6
+5533)
[warning] testing whether 'nobody' is able to -rwx /home/Plankton/mod_
+perl/mod_perl-1.99_13/t
/usr/bin/perl -Mlib=/home/Plankton/mod_perl/mod_perl-1.99_13/Apache-Te
+st/lib -MApache::TestRun -e 'eval { Apache::
TestRun::run_root_fs_test(65534, 65533, q[/home/Plankton/mod_perl/mod_
+perl-1.99_13/t]) }';


[warning] result: OK
/usr/local/apache2/bin/httpd -d /home/Plankton/mod_perl/mod_perl-1.99_
+13/t -f /home/Plankton/mod_perl/mod_perl-1.9
9_13/t/conf/httpd.conf -D APACHE2 -D PERL_USEITHREADS
using Apache/2.0.48 (prefork MPM)

waiting 120 seconds for server to start: ....[Sun Apr 25 15:05:42 2004
+] [info] 27 Apache:: modules loaded
[Sun Apr 25 15:05:42 2004] [info] 5 APR:: modules loaded
[Sun Apr 25 15:05:42 2004] [info] base server + 16 vhosts ready to run
+ tests
.......
waiting 120 seconds for server to start: ok (waited 10 secs)
server localhost:44444 started
server localhost:44445 listening (TestModperl::merge)
server localhost:44446 listening (TestModperl::perl_options)
server localhost:44447 listening (TestModperl::setupenv)
server localhost:44448 listening (TestVhost::config)
server localhost:44449 listening (TestProtocol::echo)
server localhost:44450 listening (TestProtocol::echo_filter)
    .
    .
    .
server localhost:44464 listening (TestDirective::perlloadmodule6)
t/apache/add_config....request has failed (the response code was: 500)
see t/logs/error_log for more details
dubious
        Test returned status 111 (wstat 28416, 0x6f00)
Scalar found where operator expected at (eval 171) line 1, near "'int'
+  $__val"
        (Missing operator before   $__val?)
[warning] server localhost:44444 shutdown
[  error] error running tests (please examine t/logs/error_log)
+--------------------------------------------------------+
| Please file a bug report: http://perl.apache.org/bugs/ |
+--------------------------------------------------------+
make: *** [run_tests] Error 1
linux:/home/Plankton/mod_perl/mod_perl-1.99_13 #
linux:/home/Plankton/mod_perl/mod_perl-1.99_13 # cat t/logs/error_log 
END in modperl_extra.pl, pid=5726
[Sun Apr 25 15:05:49 2004] [notice] Apache/2.0.48 (Unix) mod_perl/1.99
+_13 Perl/v5.8.0 configured -- resuming normal operations
[Sun Apr 25 15:05:49 2004] [info] Server built: Feb 26 2004 22:37:51
[Sun Apr 25 15:05:49 2004] [debug] prefork.c(1037): AcceptMutex: sysvs
+em (default: sysvsem)
[Sun Apr 25 15:05:51 2004] [error] server reached MaxClients setting, 
+consider raising the MaxClients setting
[Sun Apr 25 15:05:54 2004] [info] Child process pid=5733 is exiting
[Sun Apr 25 15:05:54 2004] [info] Child process pid=5730 is exiting
[Sun Apr 25 15:05:54 2004] [info] removed PID file /home/Plankton/mod_
+perl/mod_perl-1.99_13/t/logs/httpd.pid (pid=5728)
[Sun Apr 25 15:05:54 2004] [notice] caught SIGTERM, shutting down
END in modperl_extra.pl, pid=5728
[download]

Can you give me another hint? Thanks much!