Simulate Fences

Here's a datapoint regarding graphics performance affected by setting/not setting Simulate Fences:

Graphics card: NVIDA 8800 GTS (driver version: 7.15.11.6369).

With Simulate Fences false:

Splashscreen fadein/fadeout chugs really slowly
game screen (2D with bouncing ball and some GUI controls): ~300fps

With Simulate Fences true:

Splashscreen fadein/fadeout behaves properly
game screen (2D with bouncing ball and some GUI controls): ~62fps

In either case:
If I drag game window to second monitor, it crashes in TorqueEngineComponent.ca.Draw on
line GFXDevice.Instance.Device.SetRenderTarget(0, _mainRenderTarget.Instance); with error:
Cannot access a disposed object.
Object name: 'RenderTarget2D'.

Note: in Torque 1.5, it only crashed with Simulate Fences true (and dragging to the second monitor).