This may not be your problem, but it does look suspiciuous:

my $dbConnectString = '(LOAD_BALANCE=on)'|| 
                      '(ADDRESS=(PROTOCOL=TCP)(HOST=myhost1)(PORT=1521
+))'||
                      '(ADDRESS=(PROTOCOL=TCP)(HOST=myhost2)(PORT=1521
+))'||
                      '(CONNECT_DATA=(SERVICE_NAME=pcipJDBC.oracle.com
+))';
print "dbConnectString=$dbConnectString\n";

__END__
dbConnectString=(LOAD_BALANCE=on)
[download]

Does $dbConnectString really contain what you want? What are all those "||" operators for?