MacBook – setting to make the Mac not change resolution when connecting to an external display

I think it's expected behavior. The problem is that when the monitor sleeps, it is essentially being "unplugged" so the computer thinks it's gone. And when you reawaken it, the computer thinks a new monitor is being plugged in so it defaults to a supported resolution, but it's getting conflicting reports from the monitor and the DVI Link unit. Try to remove the DVI adapter and, instead, try to force your resolution using Display Maestroy (http://www.koingosw.com/products/displaymaestro.php)

I have got the same problem. It is not that big of a deal to change it everytime, but it still is pretty annoying.

Sometimes it doesn't happen, but most of the times it does.

This morning when I turned on my macbook, it started in my "more space" resolution. When I connected my second screen, display mirroring was turned on (something I never use and don't want). When I turned off display mirroring, my Macbook display went to the default resolution. I changed it back to "more space". Then I unplugged the second monitor. After my Macbook's screen went black, it returned in the default resolution again. I changed it back to "more space". Then I replugged my second monitor and this time it remembered my "more space" setting. I then unplugged the second monitor again and again it remembered by "more space" setting.

It seems as though it remembers the settings until I completely shut down my Macbook. Then, it reverts to the default settings (and sometimes randomly turns on display mirroring). I have to test this thesis more to see if I am correct.