This error can be caused by timeouts - either due to too much traffic on Apple's severs, or firewalls or antivirus software interfering, or incompatible third party software installed, or simply the Energy Server kicking in too early. Try to temporarily disabling firewalls like Little Snitch, antivirus software, and the Energy Saver in the System Preferences.
Check the system status at Apple's page: http://www.apple.com/support/systemstatus/
For iPhoto books it usually helpes to boot the computer into Safe Mode, before trying to order Print products. Safe mode will disable third-party extensions and Preference panes, so some problems with incompatible software will be prevented. Only, Aperture will be terribly slow in Safe mode, if you can launch it at all. But booting into Safe Mode may help to clear some settings, even if you have to reboot again back to normal mode, so give it a try.
Perhaps this time-out glitch is related to the end of daylight saving time in Australia. Check your settings for date and time in the System preferences, also your location settings in System Preferences > Language&Region. your region should be set to australia, if you are ordering from an Australian Store.