canvas

That's weird because I was just setting up something similar. I have a main canvas and another canvas on a small popup window, and altenate drawing depending on if the popup is open.

I tested it first using this as a test case and it seems to work fine, not sure if it will help though:

Global gWindow:TGadget
Global gCanvas1:TGadget
Global gCanvas2:TGadget

gWindow = CreateWindow("Dual Canvas Test",10,10,800,600)
gCanvas1 = CreateCanvas(20,20,200,150,gWindow)
gCanvas2 = CreateCanvas(20,220,200,150,gWindow)

ActivateGadget(gCanvas1)
SetGraphics CanvasGraphics(gCanvas1)
EnablePolledInput()
While KeyHit(KEY_ESCAPE) = False

	ActivateGadget(gCanvas1)
	SetGraphics CanvasGraphics(gCanvas1)

	DrawText("HELLO FROM CANVAS 1",10,10)
	Flip

	Delay 1000
	Cls
	Flip

	ActivateGadget(gCanvas2)
	SetGraphics CanvasGraphics(gCanvas2)

	DrawText("HELLO FROM CANVAS 2",10,10)
	Flip

	Delay 1000
	Cls
	Flip
	
Wend