I've just been looking at the INDI ASI driver for ccds. In that code, they trap this error and restart the image up to 3 times - might be worth restarting the image on failure and seeing if that works - or do you get failure every time you try and take an image?
Thanks for your reply and sorry for the delay in responding. I've been really busy with work...
Yes, I do restart the exposure routine once a failure is detected. It's just that the failures continue.