Index: /trunk/src/VBox/Main/src-server/StorageControllerImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/src-server/StorageControllerImpl.cpp	(revision 37923)
+++ /trunk/src/VBox/Main/src-server/StorageControllerImpl.cpp	(revision 37924)
@@ -476,5 +476,5 @@
         {
             /* AHCI SATA supports a maximum of 30 ports. */
-            if ((aPortCount < 1) || (aPortCount > 30))
+            if (aPortCount < 1 || aPortCount > 30)
                 return setError(E_INVALIDARG,
                                 tr("Invalid port count: %lu (must be in range [%lu, %lu])"),
@@ -692,7 +692,7 @@
                         tr("Invalid controller type"));
 
-    if ((aPortNumber < 0) || (aPortNumber >= 30))
+    if (aPortNumber < 0 || aPortNumber >= 30)
         return setError(E_INVALIDARG,
-                        tr("Invalid port number: %l (must be in range [%lu, %lu])"),
+                        tr("Invalid port number: %ld (must be in range [%lu, %lu])"),
                         aPortNumber, 0, 29);
 
@@ -764,13 +764,12 @@
     if (FAILED(rc)) return rc;
 
-    if (   (aControllerPort < 0)
-        || (aControllerPort >= (LONG)portCount)
-        || (aDevice < 0)
-        || (aDevice >= (LONG)devicesPerPort)
+    if (   aControllerPort < 0
+        || aControllerPort >= (LONG)portCount
+        || aDevice < 0
+        || aDevice >= (LONG)devicesPerPort
        )
         return setError(E_INVALIDARG,
-                        tr("The port and/or count parameter are out of range [%lu:%lu]"),
-                        portCount,
-                        devicesPerPort);
+                        tr("The port and/or device parameter are out of range: port=%d (must be in range [0, %u]), device=%u (must be in range [0, %u])"),
+                        (int)aControllerPort, (int)portCount-1, (int)aDevice, (int)devicesPerPort-1);
 
     return S_OK;