diff --git a/checkin_notes b/checkin_notes
index 18f6ac83f0..9efa8b1e9c 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -5666,3 +5666,11 @@ David  14 June 2009
 
     html/user/
         forum_get_data.php
+
+Charlie 14 June 2009
+    - MGR: If LOCKFILE doesn't already exist, core client isn't running so skip 
+        further testing.  This avoids a very rare possible race condition and is 
+        more efficient.
+
+    clientgui/
+        BOINCClientManager.cpp
diff --git a/clientgui/BOINCClientManager.cpp b/clientgui/BOINCClientManager.cpp
index 1beed6749f..dddde9bf93 100644
--- a/clientgui/BOINCClientManager.cpp
+++ b/clientgui/BOINCClientManager.cpp
@@ -144,10 +144,12 @@ bool CBOINCClientManager::IsBOINCCoreRunning() {
     static FILE_LOCK file_lock;
     
     sprintf(path, "%s/%s", (char *)wxGetApp().GetDataDirectory().char_str(), LOCK_FILE_NAME);
-    if (file_lock.lock(path)) {
-        running = true;
-    } else {
-        file_lock.unlock(path);
+    if (boinc_file_exists(path) {   // If there is no lock file, core is not running
+        if (file_lock.lock(path)) {
+            running = true;
+        } else {
+            file_lock.unlock(path);
+        }
     }
 #endif
     wxLogTrace(wxT("Function Status"), wxT("CBOINCClientManager::IsBOINCCoreRunning - Returning '%d'"), (int)running);