Transmission

Anyway ... Transmission didn't block sleep so I downloaded Caffeine which now blocks sleep when downloading.

I'd say also the hard drive (System Settings = Put hard disks to sleep when possible).

Nope, I don't close the lid. I just leave it alone.

But of course I have in System settings configured that it automatically goes to sleep after 15 minutes. But that's what Transmission should block, right?

Transmission 1.51

I have checked the box "Prevent sleep" but Mac still goes to sleep even with active downloads. Any ideas what might be wrong?

Thanks