Take a look at http://stackoverflow.com/questions/690071/what-are-ways-to-solve-memory-leaks-in-c/690088

>When many users using system, I found that the memory utilized by w3wp is keep increasing. Even though it is dropped sometime but it will not back to the "original" level. Therefore, I suspect memory leak.
>
>I also use profiling tool like dottrace, ANT profiler to trace what live objects are in memory and keep increasing. From there, I try to do something to release them.