We're hunting for the "load times getting longer over time" which would likely indicate a leak, and yes, it will take a while to fix most likely. Memory leaks are insidious because it could be anything, because once it's leaked, it's leaked - it could be the act of transitioning, it could be the act of opening doors or pressing tab to highlight objects - it could, literally, be anything. They also take time to fix + test, because if they are fixed incorrectly, the game will often simply crash instead of leaking.
To be clear, there is at least two seperate problems with "slow load times" - AMD phenom CPUs apparently have some inherent issues (
see this thread for how to resolve the problem)
The comments about quicksaving causing the slowdowns to go away would also indicate another, seperate problem, most likely.
We are investigating all three of these issues.