Memory Leak

[klem]

I am wondering about the nature of this memory leak. In a utility I have called Membooster, which optimises memory to recover isolated unused memory, I see two things (also it can be seen in Task Manager). On the one hand the memory usage creeps up with time but I also see a quick 'ramp up' of memory usage over a minute or two, about a 40 degree slope, before it drops vertically back to what it was. I can't find a consistent cause for this.

Is anyone else seeing this 'ramping'?
Does anyone know if it is the game or some other service?

I also tried Gamebooster to close down unecessary services but it still happens.