Goes to Sleep


Recently my computer goes into the sleep mode while it is performing a task, such as a batch conversion with Graphic Converter or printing pictures. I have not changed the settings and it should only go to sleep if idle for 30 mn. I have had my Mac OS X for 6 months and have used Graphic Converter many many times without problems.
Thank you.
Are you using a laptop? Laptops will automatically sleep if the battery is low. They also have two sets of power configurations - one for battery and one for power-adapter. You might have configured one of these profiles and not the other.
No, I am not using a laptop. It's the new G-5 and the problem is getting worse! Any ideas?