Today I tried to upgrade my Mac from 10.5.3 to 10.5.4 using normal Software Update. That didn’t go as planned as installation hanged at “Configuring Installation” and only thing I could do is shutdown the computer.

After some research and few unsuccessful retries I have finally managed to solve the upgrade problem by downloading standalone 10.5.4 update from Apple download section; booting in safe mode (hold shift key when booting) and then installing the update.