diff --git a/profile/src/nsProfile.cpp b/profile/src/nsProfile.cpp
index 57884a27f124..be775ec9e1b3 100644
--- a/profile/src/nsProfile.cpp
+++ b/profile/src/nsProfile.cpp
@@ -1198,7 +1198,24 @@ nsProfile::RenameProfile(const PRUnichar* oldName, const PRUnichar* newName)
     // Delete old profile entry
     rv = DeleteProfile(oldName, PR_FALSE /* don't delete files */);
     if (NS_FAILED(rv)) return rv;
-         
+     
+	/* note, we do not rename the dir on disk to the new name
+	 * we don't rename the directory on purpose.
+	 * we don't require the directory name to match the profile name, 
+	 * but it usually does.  
+	 * (the pairing of values occurs in the profile registry)
+	 * 
+	 * Imagine this scenario:
+	 * 1) user creates a profile "foo" and the directory gets named "foo".
+ 	 * 2) user creates a profile "bar" and the directory gets named "bar"
+	 * 3) user deletes the profile "foo", but chooses not to delete the files on disk.  (they are given this option when deleting a profile)
+	 * 4) user renames "bar" profile to "foo"
+	 * 
+	 * things would not work correctly if we renamed the folder on disk.
+	 * for completeness:
+	 *  if the user now creates another new profile named "foo", the folder on disk will have a unique name on disk, probably "foo-1".
+	 */
+    
     /* profile is just replaced. But Keep up the count */
     gProfileDataAccess->mNumProfiles++;