My tutorial uses 10uF and 22uF capacitors, which I got off a MAX232 datasheet - and it works fine. Try checking the voltages around the chip, I think pin 2 should be +10V, and pin 6 should be -10V.
My tutorials include an example for the 16F876/7, the 877a should run that without any changes to the code - it's designed so any extra facilities have to be "turned on", rather than the usual MicroChip method of them being on by default!.