That's a nice shot of M81/82 Mike. I had exactly the same issue with Maxim and a Nikon D750. I've used Maxim for years with my QSI683 but recently borrowed the D750 DSLR to try it out.
After a lot of gnashing of teeth and wringing of hands, I decided to look around for something else that could do the job.
After a bit of searching I came across this http://digicamcontrol.com/
Here are the plus points:
• It’s free (whoopee – I like free)
• It has a specific module aimed at astronomy. For example:
o you can tell it how many pictures to take
o the exposure
o optionally leave a delay between each one
o specify the format (RAW, jpeg etc)
o decide whether to leave the pictures on the camera or download them to your PC (I think it may only be Windows – not MAC)
• It handled my Nikon D750 and I think it will handle many camera types
• It even has a PHD interface but I haven’t explored that
The only ‘funny’ I found was I had to specify the ISO setting on the camera when using the astronomy module – but that is no big deal as I would normally leave that set for the entire session.
I read reviews and also got my Norton to virus check it and I believe it to be very safe.
The documentation is a little scant but I intend to use it over the next few coming days. If it works out ok I may give the guys a donation!
Hope that Helps - good luck!