diff --git a/core/model/Database.php b/core/model/Database.php
index 8f62b9ac5..818c3d466 100755
--- a/core/model/Database.php
+++ b/core/model/Database.php
@@ -175,13 +175,15 @@ abstract class Database extends Object {
 	 * if it doesn't already exist
 	 */
 	protected function transInitTable($table) {
-		if(!$this->schemaUpdateTransaction[$table]) $this->schemaUpdateTransaction[$table] = array(
-			'command' => 'alter',
-			'newFields' => array(),
-			'newIndexes' => array(),
-			'alteredFields' => array(),
-			'alteredIndexes' => array(),
-		);		
+		if(!isset($this->schemaUpdateTransaction[$table])) {
+			$this->schemaUpdateTransaction[$table] = array(
+				'command' => 'alter',
+				'newFields' => array(),
+				'newIndexes' => array(),
+				'alteredFields' => array(),
+				'alteredIndexes' => array(),
+			);
+		}		
 	}
 	
 	
@@ -247,6 +249,8 @@ abstract class Database extends Object {
 	 * @param string|boolean $spec The specification of the index. See requireTable() for more information.
 	 */
 	function requireIndex($table, $index, $spec) {
+		$newTable = false;
+		
 		if($spec === true) {
 			$spec = "($index)";
 		}
@@ -277,6 +281,8 @@ abstract class Database extends Object {
 	 * @param string $spec The field specification.
 	 */
 	function requireField($table, $field, $spec) {
+		$newTable = false;
+		
 		Profiler::mark('requireField');
 		// Collations didn't come in until MySQL 4.1.  Anything earlier will throw a syntax error if you try and use
 		// collations.
diff --git a/core/model/MySQLDatabase.php b/core/model/MySQLDatabase.php
index c3a346e76..5c8feda0e 100644
--- a/core/model/MySQLDatabase.php
+++ b/core/model/MySQLDatabase.php
@@ -178,7 +178,7 @@ class MySQLDatabase extends Database {
 	 * @param $alteredFields Updated fields, a map of field name => field schema
 	 * @param $alteredIndexes Updated indexes, a map of index name => index type
 	 */
-	public function alterTable($table, $newFields, $newIndexes, $alteredFields, $alteredIndexes) {
+	public function alterTable($tableName, $newFields, $newIndexes, $alteredFields, $alteredIndexes) {
 		$fieldSchemas = $indexSchemas = "";
 		
 		if($newFields) foreach($newFields as $k => $v) $alterList[] .= "ADD `$k` $v";