Consider the following scenario:
In this scenario, the memory usage of the Microsoft Systems Management Server (SMS) Agent Host service (Ccmexec.exe) keeps increasing.
There's a hotfix for this issue and you can read all the details and download it here:
KB973499 - A memory leak occurs when many content location requests are received by a site server that is running System Center Configuration Manager 2007 SP1
J.C. Hornbeck | Manageability Knowledge Engineer