*DISCLAIMER: THIS IS REPORTED FIXED IN IIS 8.0*
I work with the ServerManager class from the Microsoft.Web.Administration assembly quite a bit on a project for work. We use it to track websites performance, etc… After looking in dotPeek I found out that this assembly is just a COM wrapper for IIS management. As I started deploying this software to servers with more websites, I noticed that the memory growth for my monitoring process was going through the roof (usually runs with 90-150mb memory, I had instances over 9gb of memory).