diff --git a/src/cl_backend.h b/src/cl_backend.h
index 3b6ff3c..70308a1 100644
--- a/src/cl_backend.h
+++ b/src/cl_backend.h
@@ -54,11 +54,11 @@ int ptp_fsend_packets(struct PtpRuntime *r, int length, FILE *stream);
 // Reads the incoming packet to file, starting after an optional offset
 int ptp_freceive_bulk_packets(struct PtpRuntime *r, FILE *stream, int of);
 
-int ptpip_connect(struct PtpRuntime *r, char *addr, int port);
+int ptpip_connect(struct PtpRuntime *r, const char *addr, int port);
 int ptpip_cmd_write(struct PtpRuntime *r, void *data, int size);
 int ptpip_cmd_read(struct PtpRuntime *r, void *data, int size);
 
-int ptpip_connect_events(struct PtpRuntime *r, char *addr, int port);
+int ptpip_connect_events(struct PtpRuntime *r, const char *addr, int port);
 int ptpip_event_send(struct PtpRuntime *r, void *data, int size);
 int ptpip_event_read(struct PtpRuntime *r, void *data, int size);
 
diff --git a/src/cl_ops.h b/src/cl_ops.h
index d696a48..5dd75fa 100644
--- a/src/cl_ops.h
+++ b/src/cl_ops.h
@@ -5,7 +5,7 @@
 /// @brief Set a generic property - abstraction over SetDeviceProp
 /// @note May reject writes if an invalid property is found (see event code)
 /// @memberof PtpRuntime
-int ptp_set_generic_property(struct PtpRuntime *r, char *name, int value);
+int ptp_set_generic_property(struct PtpRuntime *r, const char *name, int value);
 
 /// @brief Call before taking a picture - this is generally for 'focusing'
 /// On some cameras this does nothing.
diff --git a/src/data.c b/src/data.c
index 59743ab..8b24896 100644
--- a/src/data.c
+++ b/src/data.c
@@ -109,7 +109,7 @@ int parse_data_data_or_u32(uint8_t *d, int type, uint32_t *u32, void **data) {
 	case PTP_TC_UINT16:
 	case PTP_TC_INT32:
 	case PTP_TC_UINT32:
-		return ptp_parse_data_u32(d, type, u32);
+		return ptp_parse_data_u32(d, type, (int *)u32);
 	case PTP_TC_INT64:
 	case PTP_TC_UINT64:
 		(*data) = malloc(8);
diff --git a/src/generic.c b/src/generic.c
index 22edd27..f9e7542 100644
--- a/src/generic.c
+++ b/src/generic.c
@@ -50,7 +50,7 @@ static int ptp_eos_set_validate_prop(struct PtpRuntime *r, int prop_code, uint32
 	return ptp_eos_set_prop_value(r, prop_code, value);
 }
 
-int ptp_set_generic_property(struct PtpRuntime *r, char *name, int value) {
+int ptp_set_generic_property(struct PtpRuntime *r, const char *name, int value) {
 	int dev = ptp_device_type(r);
 	int rc = 0;
 	if (!strcmp(name, "aperture")) {
diff --git a/src/ip.c b/src/ip.c
index c16607d..1bdc399 100644
--- a/src/ip.c
+++ b/src/ip.c
@@ -123,13 +123,14 @@ static struct PtpIpBackend *init_comm(struct PtpRuntime *r) {
 	return (struct PtpIpBackend *)r->comm_backend;
 }
 
-int ptpip_connect(struct PtpRuntime *r, char *addr, int port) {
+int ptpip_connect(struct PtpRuntime *r, const char *addr, int port) {
 	int fd = ptpip_new_timeout_socket(addr, port);
 
 	struct PtpIpBackend *b = init_comm(r);
 
 	if (fd > 0) {
 		b->fd = fd;
+		r->io_kill_switch = 0;
 		return 0;
 	} else {
 		b->fd = 0;
@@ -137,7 +138,7 @@ int ptpip_connect(struct PtpRuntime *r, char *addr, int port) {
 	}
 }
 
-int ptpip_connect_events(struct PtpRuntime *r, char *addr, int port) {
+int ptpip_connect_events(struct PtpRuntime *r, const char *addr, int port) {
 	int fd = ptpip_new_timeout_socket(addr, port);
 
 	struct PtpIpBackend *b = init_comm(r);
diff --git a/src/lib.c b/src/lib.c
index 8b07aa0..860bae4 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -106,7 +106,7 @@ void ptpusb_free_device_list(struct PtpDeviceEntry *e) {
 
 int ptp_buffer_resize(struct PtpRuntime *r, size_t size) {
 	if (size < r->data_length) {
-		ptp_panic("You cannot downside the data buffer");
+		ptp_panic("You cannot downsize the data buffer (%u -> %u)", r->data_length, size);
 	}
 	// realloc with a little extra space to minimize reallocs later on
 	static int extra = 100;
diff --git a/src/no_ip.c b/src/no_ip.c
index 45c5f74..d669aee 100644
--- a/src/no_ip.c
+++ b/src/no_ip.c
@@ -7,11 +7,11 @@ int ptpip_new_timeout_socket(char *addr, int port) {
 	return -1;	
 }
 
-int ptpip_connect(struct PtpRuntime *r, char *addr, int port) {
+int ptpip_connect(struct PtpRuntime *r, const char *addr, int port) {
 	return -1;
 }
 
-int ptpip_connect_events(struct PtpRuntime *r, char *addr, int port) {
+int ptpip_connect_events(struct PtpRuntime *r, const char *addr, int port) {
 	return -1;
 }
 
diff --git a/src/operations.c b/src/operations.c
index 81dec51..77f2837 100644
--- a/src/operations.c
+++ b/src/operations.c
@@ -221,10 +221,16 @@ int ptp_get_object_handles(struct PtpRuntime *r, int id, int format, int in, str
 	cmd.params[1] = format;
 	cmd.params[2] = in;
 
+	ptp_mutex_keep_locked(r);
+
 	int rc = ptp_send(r, &cmd);
+	if (rc) goto end;
 
 	(*a) = dup_uint_array((void *)ptp_get_payload(r));
 
+	end:;
+	ptp_mutex_unlock(r);
+
 	return rc;
 }
 
@@ -253,11 +259,16 @@ int ptp_get_prop_desc(struct PtpRuntime *r, int code, struct PtpPropDesc *pd) {
 	cmd.param_length = 1;
 	cmd.params[0] = code;
 
-	int x = ptp_send(r, &cmd);
+	ptp_mutex_keep_locked(r);
+	int rc = ptp_send(r, &cmd);
+	if (rc) goto end;
 
 	ptp_parse_prop_desc(r, pd);
 
-	return x;
+	end:;
+	ptp_mutex_unlock(r);
+
+	return rc;
 }
 
 int ptp_get_thumbnail(struct PtpRuntime *r, int handle) {
diff --git a/src/transport.c b/src/transport.c
index 20f2f89..bedca9a 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -42,7 +42,7 @@ int ptpip_read_packet(struct PtpRuntime *r, int of) {
 	int rc = 0;
 	int read = 0;
 
-	while (rc <= 0 && r->wait_for_response) {
+	while (r->wait_for_response) {
 		rc = ptpip_cmd_read(r, r->data + of + read, 4);
 
 		r->wait_for_response--;
@@ -50,7 +50,7 @@ int ptpip_read_packet(struct PtpRuntime *r, int of) {
 		if (rc > 0) break;
 
 		if (r->wait_for_response) {
-			ptp_verbose_log("Trying again...");
+			ptp_verbose_log("Trying again...\n");
 			CAMLIB_SLEEP(CAMLIB_WAIT_MS);
 		}
 	}
@@ -126,7 +126,7 @@ int ptpip_receive_bulk_packets(struct PtpRuntime *r) {
 			return PTP_IO_ERR;
 		}
 	} else if (h->type == PTPIP_COMMAND_RESPONSE) {
-		ptp_verbose_log("Recieved response packet\n");
+		ptp_verbose_log("Received response packet\n");
 	} else {
 		ptp_verbose_log("Unexpected packet: %X\n", h->type);
 		return PTP_IO_ERR;
@@ -167,7 +167,7 @@ int ptpusb_read_all_packets(struct PtpRuntime *r) {
 		if (rc < 0) break;
 
 		if (r->wait_for_response) {
-			ptp_verbose_log("Trying again...");
+			ptp_verbose_log("Trying again...\n");
 			CAMLIB_SLEEP(CAMLIB_WAIT_MS);
 		}
 	}
@@ -218,7 +218,7 @@ int ptpipusb_read_packet(struct PtpRuntime *r, int of) {
 	int rc = 0;
 	int read = 0;
 
-	while (rc <= 0 && r->wait_for_response) {
+	while (r->wait_for_response) {
 		rc = ptpip_cmd_read(r, r->data + of + read, 4);
 
 		r->wait_for_response--;
@@ -226,7 +226,7 @@ int ptpipusb_read_packet(struct PtpRuntime *r, int of) {
 		if (rc > 0) break;
 
 		if (r->wait_for_response) {
-			ptp_verbose_log("Trying again...");
+			ptp_verbose_log("Trying again...\n");
 			CAMLIB_SLEEP(CAMLIB_WAIT_MS);
 		}
 	}
@@ -308,6 +308,7 @@ int ptpipusb_receive_bulk_packets(struct PtpRuntime *r) {
 }
 
 int ptp_receive_bulk_packets(struct PtpRuntime *r) {
+	if (r->io_kill_switch) return -1;
 	if (r->connection_type == PTP_IP) {
 		return ptpip_receive_bulk_packets(r);
 	} else if (r->connection_type == PTP_USB) {