There used to be a memory leak in VFP when calling COM, as documented in this link. Not sure if it is fixed in later versions.

http://support.microsoft.com/kb/197206


>We are having a problem with a server written in VFP running on a Win Server 2003 box with a 3.2 GHz dual core processor and 2 GB memory. The VFP server instantiates a COM server. The COM server handles communications with one or more clients or simulators across the internet. With the server running and one client connected, we run a simulator that sends a small amount of data (34 packets of about 50 bytes each every 5 seconds) across the network to the server and the server in turn sends the data out to the one connected client. For the first 3 or 4 minutes all seems fine. The CPU usage is below 1% and the memory used by the COM Server's process os about 4-5mb.
>
>As time goes on however, the CPU usage slowly creeps up and the memory used by the process does the same. After about 4-5hrs the communications layer stops responding because of high CPU usage.
>
>What could be causing this? Or alternately, If I wanted to cause this behavior in VFP what are some ways I could go about it? If I know that I might have a clue as to where to start...
>
>Thanks,
>
>Steve