Cannot rotate camera all the way in both directions

[darthvader45]

In one direction, I can rotate the camera 360 degrees, yet in the other way it only goes 90 degrees. Which makes the game virtually unplayable, as one wrong turn means I get cronched by 173 early in the game (173 shouldn't be a problem for a veteran like me).

Using Windows 10 and SCP CB version 1.3.11