Okay, so I know the game is well old now, but I'm having an odd graphical glitch on my PC that maybe someone can explain for me.

Whenever I use a hot key to swap weapons, I get a weird animation. Instead of lowering the current weapon out of sight, it seems to fly off quickly to the top left of the screen before being replaced by the previous weapon. It doesn't do it when swapping between a pistol and a rifle, but it does it between any pistol, and it does it between rifles and baseball bats.

I owned the game on the PS3 a long time ago and don't remember it doing that. Any idea what might be causing it?

I have no add ons or mods installed, only the base game and retail DLC packs.