I had some similar issues awhile ago.
I never did find the culprit, but it was definitely in the image train - either the filters (number 1 suspect) or the camera.
Attached some similar issues I had. Also:
http://core-au.net/astro/Collection/M78/100.jpg
Try removing all filters and taking a test shot to see if it still occurs.
My issue got worse and I ended up with lines/massive spikes through bright objects (mostly stars).