Hmm... that looks like light contamination. Make sure the shutter is closing properly, and if you are taking the images in a brightly-lit area cover the camera in a dark cloth. Also just in case make sure all drivers and software are up-to-date.
The shutter is working fine, I redid the same exposure today with the end capped off instead of attached to my SCT with the end cover in place and the results look alot better.
Okay I'm going to put that down to a simple light leak. The cameras are not designed to be completely light-tight in full daylight. Light can bounce around inside the camera and get past the shutter if it is bright enough. Even though the inside of the camera is blackened, these cameras are very sensitive.
