Index: /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR3LibSharedFolders.cpp
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR3LibSharedFolders.cpp	(revision 44140)
+++ /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR3LibSharedFolders.cpp	(revision 44141)
@@ -200,4 +200,9 @@
     }
 
+    /* In this case, just return success with 0 mappings */
+    if (   rc == VERR_INVALID_PARAMETER
+        && fAutoMountOnly)
+        rc = VINF_SUCCESS;
+
     *ppaMappings = ppaMappingsTemp;