resolution changes when window is positioned too low

Hello,

When I launch a Parallels virtual machine, sometimes the window opens at a low position on my screen, too low for the entire VM window to fit on my screen. In that case, rather than extending off the bottom of my screen, Parallels lowers the resolution in the VM OS so that the window fits on my screen.

I have some VMs running on a shared computer and then my staff is accessing them via VNC. In this situation, my users are not able to move the VM windows, so they're stuck with these lower resolutions.

Is there any way to lock down the resolution inside my VM so that Parallels can't change it? I've tried all the video and display settings I can find in Parallels, but nothing seems to address this particular issue.

Thanks,
-Arlo