diff --git a/configure.in b/configure.in
index 892d56b..4f73cde 100644
--- a/configure.in
+++ b/configure.in
@@ -14,8 +14,8 @@ dnl micro version = incremented when implementation-only
 dnl                 changes are made
 dnl ---
 JACK_MAJOR_VERSION=0
-JACK_MINOR_VERSION=97
-JACK_MICRO_VERSION=2
+JACK_MINOR_VERSION=98
+JACK_MICRO_VERSION=0
 
 dnl ---
 dnl HOWTO: updating the jack protocol version
diff --git a/jack/engine.h b/jack/engine.h
index 08493d1..77000c9 100644
--- a/jack/engine.h
+++ b/jack/engine.h
@@ -150,6 +150,7 @@ struct _jack_engine {
 jack_engine_t  *jack_engine_new (int real_time, int real_time_priority,
 				 int do_mlock, int temporary,
 				 int verbose, int client_timeout,
+				 unsigned int port_max,
                                  pid_t waitpid, JSList *drivers);
 int             jack_engine_delete (jack_engine_t *);
 int             jack_run (jack_engine_t *engine);
diff --git a/jackd/engine.c b/jackd/engine.c
index 98b1725..ebb29ac 100644
--- a/jackd/engine.c
+++ b/jackd/engine.c
@@ -1927,7 +1927,7 @@ jack_server_thread (void *arg)
 
 jack_engine_t *
 jack_engine_new (int realtime, int rtpriority, int do_mlock, int temporary,
-		 int verbose, int client_timeout, pid_t wait_pid,
+		 int verbose, int client_timeout, unsigned int port_max, pid_t wait_pid,
 		 JSList *drivers)
 {
 	jack_engine_t *engine;
@@ -1955,7 +1955,7 @@ jack_engine_new (int realtime, int rtpriority, int do_mlock, int temporary,
 	engine->client_timeout_msecs = client_timeout;
 
 	engine->next_client_id = 1;
-	engine->port_max = 128;
+	engine->port_max = port_max;
 	engine->rtpriority = rtpriority;
 	engine->silent_buffer = 0;
 	engine->verbose = verbose;
diff --git a/jackd/jackd.1.in b/jackd/jackd.1.in
index 238c509..d2ba12c 100644
--- a/jackd/jackd.1.in
+++ b/jackd/jackd.1.in
@@ -45,6 +45,10 @@ These do not include driver options, which are obtained using the
 \fB\-m, \-\-no\-mlock\fR
 Do not attempt to lock memory, even if \fB\-\-realtime\fR.
 .TP
+\fB\-p, \-\-port\-max \fI n\fR
+Set the maximum number of ports the JACK server can manage.  
+The default value is 128.
+.TP
 \fB\-R, \-\-realtime\fR 
 .br
 Use realtime scheduling.  This is needed for reliable low-latency
diff --git a/jackd/jackd.c b/jackd/jackd.c
index 7cab1f9..31b5f28 100644
--- a/jackd/jackd.c
+++ b/jackd/jackd.c
@@ -60,6 +60,7 @@ static int do_mlock = 1;
 static int temporary = 0;
 static int verbose = 0;
 static int client_timeout = 500; /* msecs */
+static unsigned int port_max = 128;
 
 static void 
 do_nothing_handler (int sig)
@@ -135,7 +136,7 @@ jack_main (jack_driver_desc_t * driver_desc, JSList * driver_params)
 	/* get the engine/driver started */
 
 	if ((engine = jack_engine_new (realtime, realtime_priority, do_mlock,
-				       temporary, verbose, client_timeout,
+				       temporary, verbose, client_timeout, port_max,
 				       getpid(), drivers)) == 0) {
 		fprintf (stderr, "cannot create engine\n");
 		return -1;
@@ -345,6 +346,7 @@ static void usage (FILE *file)
 "usage: jackd [ --realtime OR -R [ --realtime-priority OR -P priority ] ]\n"
 "             [ --no-mlock OR -m ]\n"
 "             [ --timeout OR -t client-timeout-in-msecs ]\n"
+"             [ --port-max OR -p maximum-number-of-ports]\n"
 "             [ --verbose OR -v ]\n"
 "             [ --silent OR -s ]\n"
 "             [ --version OR -V ]\n"
@@ -384,6 +386,7 @@ main (int argc, char *argv[])
 		{ "driver", 1, 0, 'd' },
 		{ "verbose", 0, 0, 'v' },
 		{ "help", 0, 0, 'h' },
+		{ "port-max", 1, 0, 'p' },
 		{ "no-mlock", 0, 0, 'm' },
 		{ "realtime", 0, 0, 'R' },
 		{ "realtime-priority", 1, 0, 'P' },
@@ -465,6 +468,10 @@ main (int argc, char *argv[])
 			do_mlock = 0;
 			break;
 
+		case 'p':
+			port_max = (unsigned int) atol (optarg);
+			break;
+
 		case 'P':
 			realtime_priority = atoi (optarg);
 			break;
diff --git a/libjack/shm.c b/libjack/shm.c
index 75c04dc..13beb97 100644
--- a/libjack/shm.c
+++ b/libjack/shm.c
@@ -119,7 +119,9 @@ jack_cleanup_shm (void)
 		
 		if (destroy) {
 
-			jack_destroy_shm (&copy);
+			if (copy.index >= 0  && copy.index < MAX_SHM_ID) {
+				jack_destroy_shm (&copy);
+			}
 			r->size = 0;
 			r->allocator = 0;
 		}