Seriously, why all the jitters and flashes?

what I really need is a way to keep the backbuffer from getting overwritten by the front buffer

Make a new buffer and use that instead. eg...

WIDTH=800
HEIGHT=600

Graphics WIDTH,HEIGHT,0,1
screenBuffer=CreateImage(WIDTH,HEIGHT)

While Not KeyHit(1)
SetBuffer ImageBuffer(screenBuffer)
Color Rand(50,255),Rand(50,255),Rand(50,255)
Plot Rand(0,WIDTH-1),Rand(0,HEIGHT-1)

SetBuffer BackBuffer()
DrawBlock screenBuffer,0,0
Flip

Wend