You'd better tell us about the box, chipset, and the software, and not the book.
2006 is old now for a linux version. 8254 is very old for a serial device - they are the buffered 16550a ones now, or copies of same in the asic.
You're probably better reinstalling than fixing if it's a major issue. Can you set the thing using setserial? I think IO-APICs have come a bit since then. If yours is a VIA chipset, there could even be hardware issues with yours as there was with mine.