Third Party Mod Saving Bug

[KagePrototype]

Whenever I try to load a quicksave or an autosave for third party mods, the map loads, but most or all of the entities seem to not work. Lighting is there obviously, but enemies don't react, even when shot, some doors don't open, ladders don't work, level transistions don't work...If you shoot enemies, grey blood appears instead of red or yellow, and they don't move. They just say things like "argh, you got me!" etc. As for normal saves (i.e. going into the menu and doing it manually), they simply don't load at all.

[EDIT]: In fact, sometimes quick saves and autosaves refuse to load as well.

This only happens on third party mods as far as I'm aware (despite all the other bugs I'm getting from Half-Life and Opposing Force, they don't have it)

Relevant spec:

Windows XP Pro
Althon 2700XP+
512MB DDR
Radeon 9600 Pro