I mentioned "memory leak" because the game uses over 3GB of ram for me(see my reply after the one you qouted). There is no way in hell a game of this scale needs even close to 2GB of system ram to run smoothly, let alone 3+. GTA 4 doesn't even come close to that amount.
That certainly smells like a memory leak, especially when the GB used increases over time(watch your task manager). However, I have noticed it not using as much ever since taming my save files...so they are related.