[abz10]

It occurred in both Windows and Ubuntu. In Windows “Never” wasn’t an option for Sleep (edit; I forget if it wasn’t an option or selecting it didn’t work), in Ubuntu the usual disable sleep commands didn’t work. Someone in the Ubuntu forums suggested there was a recent power management change due to EU reg and the code around it was freshly buggy. I spent a day on it before cutting my losses.

[techrat]

It's software that triggers the sleep state, not the hardware.

Sounds more or less like you were using the desktop OS version for a server device.

[emodendroket]

Even in the case where this were really true there are programs like "Caffeine" which will fool your machine into thinking it's not idle.