That's a "read the bloomin' manual" moment, Cees... On page 2, indeed, with big red writing saying "Don't Panic!" - It does explain why in there and it really isn't a problem, just the way that FSX handles animations. ;)
On the other hand, I can confirm the orange box around the spinner and the weird transparency on the smoke. I thought the latter was just my PC being slow loading textures at first, but having restarted the box and tried again (without ADE, Blender, Photoshop and umpteen explorer boxes open in the background) you can actually see the texture on the textured square planes, but the transparency settings seem wrong.
I've put down incorrect fuelling trucks for the moment, so I can get X2HO out the door... So while I was at it, I threw together something for B.7 Advance...