Even when using Handbrake 1280x720 30fps anything over 18mins can be a hit or miss proposition. Most if not all my video's I upload to YoutTube are 1080p 30fps or 1080 60fps. My Let's Play video's are really the ones at issue on DTube as they are typically 20min+. My other video's are typically 3min, 4min up to maybe 12min at most.

Dtube seems to be okay with video's around 20min 1280x720, but it can be fussy. Today I was trying to upload a 24min video 1280x720 and Dtube was having none of that (FireFox). I'm trying to come up with some workarounds.