Just noticed that if you save the game when you are standing exactly on edge of a ledge, loading the savegame may end up the player dropping inside the ledge. Player is on the ledge but at the height of the surrounding floor. This happens with Vavoom r4325. Here's such a savegame from Doom2 MAP01.

This one is a strange problem, I'll investigate it later <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt=":)" title="Smile" /><!-- s:) -->.