diff --git a/core/model/DB.php b/core/model/DB.php
index 6a0e611c9..710c52e86 100755
--- a/core/model/DB.php
+++ b/core/model/DB.php
@@ -218,6 +218,16 @@ class DB {
 	static function tableList() {
 		return DB::$globalConn->tableList();
 	}
+	
+	/**
+	 * Get a list of all the fields for the given table.
+	 * Returns a map of field name => field spec.
+	 * @param string $table The table name.
+	 * @return array
+	 */
+	static function fieldList($table) {
+		return DB::$globalConn->fieldList($table);
+	}
 
 	/**
 	 * Enable supression of database messages.
@@ -226,4 +236,4 @@ class DB {
 		return DB::$globalConn->quiet();
 	}
 }
-?>
\ No newline at end of file
+?>
diff --git a/core/model/DataObject.php b/core/model/DataObject.php
index 31d163a76..f7b0d7063 100644
--- a/core/model/DataObject.php
+++ b/core/model/DataObject.php
@@ -528,7 +528,7 @@ class DataObject extends Controller {
 			}
 
 			// Divvy up field saving into a number of database manipulations
-			if(is_array($ancestry)) {
+			if(isset($ancestry) && is_array($ancestry)) {
 				foreach($ancestry as $idx => $class) {
 					$classSingleton = singleton($class);
 					foreach($this->record as $fieldName => $value) {
@@ -1861,4 +1861,4 @@ class DataObject extends Controller {
 }
 
 
-?>
\ No newline at end of file
+?>
diff --git a/core/model/DatabaseAdmin.php b/core/model/DatabaseAdmin.php
index 04fa499a2..fe9357f36 100644
--- a/core/model/DatabaseAdmin.php
+++ b/core/model/DatabaseAdmin.php
@@ -65,9 +65,7 @@ class DatabaseAdmin extends Controller {
 	 * Updates the database schema, creating tables & fields as necessary.
 	 */
 	function build() {
-		if((Director::isLive() && ClassInfo::hasTable('Member') &&
-					ClassInfo::hasTable('Group') && ClassInfo::hasTable('Permission'))
-			 && (!Member::currentUser() || !Member::currentUser()->isAdmin())) {
+		if(Director::isLive() && Security::database_is_ready() && (!Member::currentUser() || !Member::currentUser()->isAdmin())) {
 			Security::permissionFailure($this,
 				"This page is secured and you need administrator rights to access it. " .
 				"Enter your credentials below and we will send you right along.");
@@ -79,8 +77,7 @@ class DatabaseAdmin extends Controller {
 			set_time_limit(600);
 		}
 
-		$this->doBuild(isset($_REQUEST['quiet']) ||
-									 isset($_REQUEST['from_installer']));
+		$this->doBuild(isset($_REQUEST['quiet']) || isset($_REQUEST['from_installer']));
 	}
 
 	/**
diff --git a/security/Security.php b/security/Security.php
index ef0ffc5f0..49cc60e35 100644
--- a/security/Security.php
+++ b/security/Security.php
@@ -834,6 +834,19 @@ class Security extends Controller {
 
 		print '</p>';
 	}
+	
+	/**
+	 * Checks the database is in a state to perform security checks.
+	 * @return bool
+	 */
+	public static function database_is_ready() {
+		return
+			ClassInfo::hasTable('Member') &&
+			ClassInfo::hasTable('Group') &&
+			ClassInfo::hasTable('Permission') &&
+			(($permissionFields = DB::fieldList('Permission')) && isset($permissionFields['Type'])) &&
+			(($memberFields = DB::fieldList('Member')) && isset($memberFields['RememberLoginToken']));
+	}
 
 }