Index: /trunk/src/VBox/Devices/Storage/DevAHCI.cpp
===================================================================
--- /trunk/src/VBox/Devices/Storage/DevAHCI.cpp	(revision 52950)
+++ /trunk/src/VBox/Devices/Storage/DevAHCI.cpp	(revision 52951)
@@ -1703,4 +1703,7 @@
     if (rc != VINF_SUCCESS)
         return rc;
+
+    /* Update interrupt status register first. */
+    ahci->regHbaIs |= ASMAtomicXchgU32(&ahci->u32PortsInterrupted, 0);
 
     if (u32Value > 0)