diff --git a/apps/px4io/i2c.c b/apps/px4io/i2c.c
index cf69211791..174ec2813b 100644
--- a/apps/px4io/i2c.c
+++ b/apps/px4io/i2c.c
@@ -242,6 +242,7 @@ i2c_rx_complete(void)
 			uint16_t *regs;
 			unsigned reg_count;
 
+			/* work out which registers are being addressed */
 			int ret = registers_get(selected_page, selected_offset, &regs, &reg_count);
 			if (ret == 0) {
 				tx_buf = (uint8_t *)regs;
@@ -250,6 +251,14 @@ i2c_rx_complete(void)
 				tx_buf = junk_buf;
 				tx_len = sizeof(junk_buf);
 			}
+
+			/* disable interrupts while reconfiguring DMA for the selected registers */
+			irqstate_t flags = irqsave();
+
+			stm32_dmastop(tx_dma);
+			i2c_tx_setup();
+
+			irqrestore(flags);
 		}
 	}
 
diff --git a/apps/px4io/registers.c b/apps/px4io/registers.c
index 0206e0db0e..6b7ef015f4 100644
--- a/apps/px4io/registers.c
+++ b/apps/px4io/registers.c
@@ -80,9 +80,9 @@ volatile uint16_t	r_page_controls[PX4IO_CONTROL_CHANNELS];
  * Static configuration parameters.
  */
 static const uint16_t	r_page_config[] = {
-	[PX4IO_P_CONFIG_PROTOCOL_VERSION]	= 0,
-	[PX4IO_P_CONFIG_SOFTWARE_VERSION]	= 0,
-	[PX4IO_P_CONFIG_BOOTLOADER_VERSION]	= 0,
+	[PX4IO_P_CONFIG_PROTOCOL_VERSION]	= 1,	/* XXX hardcoded magic number */
+	[PX4IO_P_CONFIG_SOFTWARE_VERSION]	= 1,	/* XXX hardcoded magic number */
+	[PX4IO_P_CONFIG_BOOTLOADER_VERSION]	= 3,	/* XXX hardcoded magic number */
 	[PX4IO_P_CONFIG_MAX_TRANSFER]		= 64,	/* XXX hardcoded magic number */
 	[PX4IO_P_CONFIG_CONTROL_COUNT]		= PX4IO_CONTROL_CHANNELS,
 	[PX4IO_P_CONFIG_ACTUATOR_COUNT]		= IO_SERVO_COUNT,