[oattes]

It only happens at resolutions above 1080p (as far as I can tell). On my HTPC everything is fine (1080p TV). I only noticed the issue on my desktop where I am using Kodi (for testing) in windowed mode on a 4K monitor. I'm pretty sure it's an artefact created when Kodi scales 1080p textures to high resolutions... I can't see any issue with the texture dimensions or the coordinates in the skin. Here is an example:

Hmm, this going to be very hard to reproduce for me as I do not have a 4K monitor.
Does the issue also occur if you start Kodi fullscreen on that same monitor ?
Remember that some weird stuff can happen when you switch from monitor or windowed/fullscreen, mainly because the aspect ratio changes which will not be picked up by the skin untill a reloadskin command is issued or Kodi restarted.

It does happen when Kodi is started full screen. I would be happy to try and help debug the dang thing, but at this point, unless there are a lot of folks using the skin with this particular option on a 4K TV/Monitor, I don't think it worthy of a lot of effort. I suspect that for true 4K support the entire set of textures needs to be re-worked (as with the transition from SD to HD). I may take a more careful look at the individual textures involved to see if I can finesse out some more clues, but for now, I'd suggest you put this one in the 'some day in the future' drawer ;-).

LOL, don't assume -- look! (That's me talking to myself, not to you ;-)

The textures don't have all the same height dimension (c.f. aspect ratio). Most are 60 but some are 57 -- that's the culprit. Round off during scaling takes care of the issue until you get sufficient resolution. I'll fuss with the textures and send you an updated set.