I know they tell you it isn't but...

Could it be a programming glitch where that layer is sitting at 5% or so in another cue so it is leaving a slight transparent ghost?

Does the HOG III output screen confirm that there is no level to that layer?

Does it still do it if you disconnect the DMX and use the HUD to recreate the same cue?

When you see the ghosting clip, if they changed the file at that point, can you see the image change?

I have inadvertently recorded a layer in a cue when I knocked the intensity while adjusting another parameter. Especially easy on the III as there is the intensity wheel next to the keyboard. Didn't notice until I saw the ghost over another image.

Cheers

Toby