Index: /trunk/src/VBox/Devices/Storage/DevBusLogic.cpp
===================================================================
--- /trunk/src/VBox/Devices/Storage/DevBusLogic.cpp	(revision 30808)
+++ /trunk/src/VBox/Devices/Storage/DevBusLogic.cpp	(revision 30809)
@@ -875,6 +875,5 @@
 
     /* Modify I/O address does not generate an interrupt. */
-    if (   (pBusLogic->uOperationCode != BUSLOGICCOMMAND_MODIFY_IO_ADDRESS)
-        && (pBusLogic->uOperationCode != BUSLOGICCOMMAND_EXECUTE_MAILBOX_COMMAND))
+    if (pBusLogic->uOperationCode != BUSLOGICCOMMAND_EXECUTE_MAILBOX_COMMAND)
     {
         /* Notify that the command is complete. */
@@ -1292,4 +1291,5 @@
                 pBusLogic->fISAEnabled = false;
             }
+            fSuppressIrq = true;
             break;
         }