Index: libusb10.c
===================================================================
--- libusb10.c	(revision 338454)
+++ libusb10.c	(working copy)
@@ -1465,7 +1463,13 @@
 	    (libusb20_tr_get_priv_sc1(pxfer1) == sxfer)) {
 		err = LIBUSB_ERROR_BUSY;
 	} else {
+		struct libusb_device_handle *devh;
 
+		devh = uxfer->dev_handle;
+
+		if  (libusb20_dev_check_connected(devh))
+			goto end;
+
 		/* set pending state */
 		sxfer->state = LIBUSB_SUPER_XFER_ST_PEND;
 
@@ -1479,6 +1483,7 @@
 		err = 0;		/* success */
 	}
 
+end:
 	CTX_UNLOCK(dev->ctx);
 
 	DPRINTF(dev->ctx, LIBUSB_DEBUG_FUNCTION, "libusb_submit_transfer leave %d", err);