I'm not sure if this is a hardware or software problem, however the problem started when I switched from an Orion SSAG to the SBIG STi mono, so I'm guessing it is a hardware problem and posted it in the hardware section, however please move the thread if needed. Ever since I switched from a Orion SSAG on a Borg Mini 50 guide scope to a SBIG STi mono on an OAG8300 every so often at random times I get a guide image that is pretty much all noise and no star. This does not happen when I have a very bright star, only when it is a faint star, so I initially wrote it up to a dim star or possibly clouds from time to time. However my friend that I share the observatory with is having the exact same problem, we have had the problem happen at different times while imaging in the same area of the sky. I have also noticed several other users of the same hardware describing something very similar on this forum and others, so I decided to do some more investigating. I've uploaded some images, I'm no expert here but it seems to me that on some of the images the background level is much higher than others, when this happens it causes a star fade. All of these images were taken within a short time period, there were no clouds during this time. I also attached a screenshot of my current SBIG drivers. I also have a link to a movie that I made of some of my guide images where you can see this happening. I'm running version 6.12 of Maxim. I've also uploaded my settings folder. I've seen this problem or similar problems blamed on clouds, seeing, or other external problems, but I really can not see how such a drastic change in background levels on 3 second guide exposures could be blamed on sky conditions. This video was created with MaximDL, all are 3 second guide exposures, all the screen stretch is the same at low. It is a total of 176 images over about 12 minutes of time at 2 fps. https://www.dropbox.com/s/d7wk00bo1gh6yi7/Guide Image Movie.avi?dl=0 Any other info that you need please let me know and I will be happy to provide it as I would like to get this problem fixed.