diff --git a/checkin_notes b/checkin_notes
index 4ddaf5c4b6..edefca0936 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -455,7 +455,8 @@ Charlie Jan 15 2009
     - client: boinc_copy ownership fix of 1/6/09 didn't work because it used 
         system(cp ...) call, which invokes a shell, and POSIX specifies that 
         shells run from an application use the real UID and GID not the 
-        effective UID and GID.  Changed boinc_copy to copy file directly.
+        effective UID and GID.  Under Mac Sandbox security, we need to use 
+        the effective UID and GID.  Changed boinc_copy to copy file directly.
     - MGR: On Mac, fix problems showing Manager window when it was minimized 
         to Dock, especially if window was closed using Dock menu.
     - Mac: Fix XCode project for boinc_cmd.cpp moved to client/ from lib/.