Lately, I have encountered a very annoying problem: sometimes, while flying a plane, the game will freeze, and the only way to make it unfreeze is to minimize and open the window again. I generally quickly double tap Alt + Tab to remedy this. This activity can also be seen as soon as I enter flight from the designer: the screen might be black, and the only way to fix this is to exit and enter back in. Also, behavior similar to this occurs on location switching: If I switch a location, the game freezes until I exit and reenter, switching location instantly after I exit SP from the main window. From what I noticed, no physics or anything is modeled while frozen, but as soon as I switch out, physics, loading, etc. start back up again before I switch back to SP. Control inputs such as pitch and roll are not maintained while switching, but any camera movement due to a mouse click and drag is multiplied like crazy after I switch back to SP. I noticed that when in combat, especially with combat jets against an AI, this happens about every four seconds. However, with my airship that I do not bring into combat, this occurs infrequently, even though it has many weapons. When I spawn an AI plane that is aggressive, one of two things may occur: if it has missiles, this freezing will happen more frequently; if it has guns or is unarmed, freezing will be mild at maximum.

EDIT: After some tests, this only occurs while in Fullscreen mode.