After rejecting the awesome.... I have neglected the comments.
Latent - it flipped because it went weird. It played perfectly on my computer. But when I use them on windows movie player, they play upside down! When I rotated them they seemed like a mirror. Thankfully you can't generally tell!
Hobo - I may well come round for that. All practice is good practice. Got to see how many brownie points I have left after Plymouth!