diff --git a/core/model/DataObject.php b/core/model/DataObject.php
index 7a6292b67..26f264280 100755
--- a/core/model/DataObject.php
+++ b/core/model/DataObject.php
@@ -2963,13 +2963,12 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	public static function get_by_id($callerClass, $id, $cache = true) {
 		if(is_numeric($id)) {
 			if(is_subclass_of($callerClass, 'DataObject')) {
-				$tableClasses = ClassInfo::dataClassesFor($callerClass);
-				$baseClass = array_shift($tableClasses);
-				return DataObject::get_one($callerClass,"\"$baseClass\".\"ID\" = $id", $cache);
+				$baseClass = ClassInfo::baseDataClass($callerClass);
+				return DataObject::get_one($callerClass,"\"$baseClass\".\"ID\" = $id", $cache, 1);
 
 				// This simpler code will be used by non-DataObject classes that implement DataObjectInterface
 			} else {
-				return DataObject::get_one($callerClass,"\"ID\" = $id", $cache);
+				return DataObject::get_one($callerClass,"\"ID\" = $id", $cache, 1);
 			}
 		} else {
 			user_error("DataObject::get_by_id passed a non-numeric ID #$id", E_USER_WARNING);
diff --git a/security/Member.php b/security/Member.php
index 175e485e9..eee4d4bd3 100755
--- a/security/Member.php
+++ b/security/Member.php
@@ -557,7 +557,7 @@ class Member extends DataObject {
 	static function currentUser() {
 		$id = Member::currentUserID();
 		if($id) {
-			return DataObject::get_one("Member", "\"Member\".\"ID\" = $id");
+			return DataObject::get_one("Member", "\"Member\".\"ID\" = $id", true, 1);
 		}
 	}