Index: /trunk/src/VBox/Additions/WINNT/VBoxTray/VBoxIPC.cpp
===================================================================
--- /trunk/src/VBox/Additions/WINNT/VBoxTray/VBoxIPC.cpp	(revision 50039)
+++ /trunk/src/VBox/Additions/WINNT/VBoxTray/VBoxIPC.cpp	(revision 50040)
@@ -294,4 +294,7 @@
             fListIsEmpty = RTListIsEmpty(&pCtx->SessionList);
             rc2 = RTCritSectLeave(&pCtx->CritSect);
+
+            if (!fListIsEmpty) /* Don't hog CPU while waiting. */
+                RTThreadSleep(100);
         }