Actually you will also get that error message if the path you have specified to YUI Compressor is incorrect. It is more in reference to the tmp file having not been created by YUI which means PSPad fails to find the file when it tries to open it.
-- Carbonize <http://forum.pspad.com/read.php?2,51923,51975> PSPad freeware editor http://www.pspad.com
