20 sec pause between pages – HP LaserJet

HP LaserJet 1100 is a very good printer, but sometimes it takes so long to print multi-page document, why? It has a lot of RAM, I think it should be enough to keep next page ready to print while previous is printing. But when I try to print simple 2-page Excel document (without graphics, just text and numbers), I have to wait for aproximately 20 seconds looking at the blinking LED before EVERY PAGE. And it’s not only 1100 and not only Excel. My friend has same problem with LaserJet 5L and MS Word.
How do I fix it?