Code 2,145,50

I have a Canon MX870 printer. And what a reliable machine it has been!

However, with increasing frequency I'm receiving code 2,145,50 telling me "Cannot communicate with scanner...Code 2,145,50".

Sometimes the problem is fixed by trying again but I usually have to fix the problem by turning the printer off then on.

Is the 2,145,50 gremlin really telling me I need to put my faithful printer out to pasture? Or is there a simple solution?