Index: /trunk/src/VBox/Main/src-server/MachineImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/src-server/MachineImpl.cpp	(revision 46815)
+++ /trunk/src/VBox/Main/src-server/MachineImpl.cpp	(revision 46816)
@@ -1730,10 +1730,12 @@
     mHWData->mVideoCaptureEnabled = fEnabled;
 
+    alock.release();
+    rc = onVideoCaptureChange();
+    alock.acquire();
+    if (FAILED(rc)) return rc;
+
     /** Save settings if online - @todo why is this required? -- @bugref{6818} */
     if (Global::IsOnline(mData->mMachineState))
         saveSettings(NULL);
-
-    alock.release();
-    rc = onVideoCaptureChange();
 
     return rc;