Oops!  Didn't realize that the CI super object was not being used by the main Driver.  Fixed...
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 7c59c30..985c975 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -242,8 +242,11 @@
 	 */

 	function escape_str($str)	

 	{

+		// Access the CI object

+		$CI->get_instance();

+

 		// ODBC doesn't require escaping

-		return $this->input->CI->_remove_invisible_characters($str);

+		return $CI->_remove_invisible_characters($str);

 	}

 	

 	// --------------------------------------------------------------------