I've setup Tixati (1.99 32-bit Windows) to download using the scheduler, however with any download comes a prompt which displays the actual files that will be downloaded (meta-data). I was finding that when my computer locked, the prompt never timed out and therefore my files never downloaded. What I had to do was prevent my computer from auto-locking was to play something in Windows Media Player (a wave file in a loop with the audio disabled) with the 'Allow screen saver during playback' option disabled. Then my scheduled download works as the prompt then times out.

Since I already have a work-around, I'm not too fussed on a better solution, however it would be great for other people if the prompt would still timeout and continue when a computer locks.

You can configure this prompt is Settings > User Interface > Behavior > Transfer loading priority/location prompt. There is a prompt timeout option.

I have it set to timeout after 30 seconds but when my PC is locked the timeout doesn't happen. Only when my PC is unlocked does it timeout after the specified time.