I didn't have a problem with the response time until I changed the language for non-Unicode programs to Chinese in the Windows Regional and Language options (under Vista), and then PSPad became annoyingly slow. Key repeat didn't work until the key was released, so I was backspacing a random amount of characters each time I tried, and responses to key presses were generally noticeably slower.
-- <http://forum.pspad.com/read.php?2,45421,49113> PSPad freeware editor http://www.pspad.com
