diff --git a/bootrom/bootrom.c b/bootrom/bootrom.c
index fe893e319..34fb72e51 100644
--- a/bootrom/bootrom.c
+++ b/bootrom/bootrom.c
@@ -194,17 +194,18 @@ static void flash_mode(int externally_entered) {
 	size_t rx_len;
 
 	usb_enable();
-	for (volatile size_t i=0; i<0x100000; i++) {};
+	//for (volatile size_t i=0; i<0x100000; i++) {};
 
 	for(;;) {
-		WDT_HIT();
 
 		if ( usb_poll_validate_length())  {
 			rx_len = usb_read(rx, sizeof(UsbCommand));
-			if (rx_len)
+			if (rx_len == sizeof(UsbCommand))
 				UsbPacketReceived(rx, rx_len);
 		}
 
+		WDT_HIT();
+				
 		if (!externally_entered && !BUTTON_PRESS()) {
 			/* Perform a reset to leave flash mode */
 			usb_disable();