>Is there anything I am missing ? Maybe I don't understand correctly how the memory usage work. If you have any explanation or solution, it would really help me.

It is IE spurging over in the workingset of windows, not the vfp memory space.
You can control it (sort of) by WinAPI cals trimming and resetting the workingsetsize
[although it will be gobbled up FASTER later on] or just by minimzing (can be done programmatically)
the main window (try it by hand, worked up to early in this century, left project then...).

For me the best way to handle was to stay in the "runing" part even if it meant trimming memeory
a couple of times each hour.

regards

thomas