M42 Last night poor seeing?

Poor seeing in the upper atmosphere and -2 degrees made it a difficult night with the scope. I only managed 6 images worth saving and stacked them to produce this image. I spent most of the time indoors shooting tethered to the unmodified DSLR camera.
6 x 30secs subs.
3 darks
3 lights
2 bias.
Analysing the reject subs for "jerky star trails" on my etx made me strip the RA drive today. I have found the base was tight to turn and the gear train sticking.