diff --git a/core/abstract/abstract_util.php b/core/abstract/abstract_util.php
index a6d6b1d..60afac5 100644
--- a/core/abstract/abstract_util.php
+++ b/core/abstract/abstract_util.php
@@ -59,7 +59,7 @@ abstract class Abstract_Util {
 	// --------------------------------------------------------------------------
 
 	/**
-	 * Convienience public function to generate sql for creating a db table
+	 * Convenience public function to generate sql for creating a db table
 	 *
 	 * @deprecated Use the table builder class instead
 	 * @param string $name
@@ -94,7 +94,7 @@ abstract class Abstract_Util {
 			}
 		}
 
-		// Join column definitons together
+		// Join column definitions together
 		$columns = array();
 		foreach($column_array as $n => $props)
 		{
diff --git a/drivers/firebird/firebird_util.php b/drivers/firebird/firebird_util.php
index 9f711c3..902cbaf 100644
--- a/drivers/firebird/firebird_util.php
+++ b/drivers/firebird/firebird_util.php
@@ -34,9 +34,10 @@ class Firebird_Util extends Abstract_Util {
 	 * @param string $name
 	 * @param array $fields
 	 * @param array $constraints
+	 * @param bool $if_not_exists
 	 * @return string
 	 */
-	public function create_table($name, $fields, array $constraints=array())
+	public function create_table($name, $fields, array $constraints=array(), $if_not_exists=FALSE)
 	{
 		return parent::create_table($name, $fields, $constraints, FALSE);
 	}