Actual Size View in Illustrator CS4

I use Illustrator a lot and use a Dell 24" monitor with my MacBook Pro. Whenever I'm working in Illustrator whenever I select Actual Size view it isn't an Actual size view on my monitor. For instance say I'm working on an A4 size artboard and select Actual Size when I place an A4 piece of paper in front of the artboard on my monitor they are not the same size. Does anyone know how I can calibrate so that actual size is actual size in reality? as this would so helpful when working on much larger format sizes like A0 and A1.

That's pretty normal. Has to do with different pixel densities and such.

A good workaround is to zoom in/out at 1% increments until the A4 page fills the A4 page on the screen. Then, remember that percentage and instead of going to "actual size" view, just type it in whenever you need it. Few seconds longer than clicking actual size, but it will work.