Part I: it's possible to use two-weapon combat while wielding a
lance (which seems odd to me); the second weapon would hit even if the
the first delivered a lance jousting blow that knocked the target away.
Part II: always getting the joust knockback effect when hitting
with a lance while mounted was too powerful; implement a suggestion
from the newsgroup that it be a random chance based on skill level.
Related: it's now possible to break your lance when hitting; when
adding that, I noticed that it was theoretically possible (didn't try
to reproduce) for a shattered boomerang or mirror to yield the stagger
bonus sometimes given for unarmed attacks.