diff -r 4f97d61a8671 -r fc64a4b1ec1a devices/e1000/e1000_main-2.6.28-ethercat.c
--- a/devices/e1000/e1000_main-2.6.28-ethercat.c	Wed Dec 05 11:32:45 2012 +0100
+++ b/devices/e1000/e1000_main-2.6.28-ethercat.c	Wed Dec 05 11:47:07 2012 +0100
@@ -3236,6 +3236,10 @@
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	struct e1000_tx_ring *tx_ring = adapter->tx_ring;
 
+	if (adapter->ecdev) {
+		return -EBUSY;
+	}
+
 	netif_stop_queue(netdev);
 	/* Herbert's original patch had:
 	 *  smp_mb__after_netif_stop_queue();