Pomola Software has updated Mac Shutdown X (http://pomola.com/products_macshutdown/macshutdown.html), a Mac OS X utility for shutting down a Mac on a specified event or on a specified date and time, to version 1.5.4. It’s a maintenance update with some bug fixes.
Mac Shutdown X costs US$20. Version 1.5.4 is a free update for registered users. The software is Universal Binary so runs natively on both PowerPC and Intel Macs. It requires Mac OS X 10.4 or higher.