Nothing Renders on a Loaded Game

when i load a game either by clicking the Save/Load option on the menu or by selecting Continue Game, the load screen shows up and it loads and then says "press any key to continue". then when i continue, the game "starts up", the HUD is visible, all the sounds work, but the rest of the game is black and nothing is visible. this will make the game impossible to play.

also, when i start a new game, sometimes my screen looks like this:
http://i47.tinypic.com/5mx2ki.jpg
and then sometimes it looks clear like it should:
http://i48.tinypic.com/2gx1vzq.jpg

[Feelgood]

http://forums.steampowered.com/forum....php?t=1333712