When geos first starts, it must be clearing the application state files,
which are typically total 50k-100k in size, depending on how many apps
you keep open. You should be noticing that opening apps for the first time
after a reboot are taking longer.
Part of the OGO Ram behaves like a hard drive (about half the RAM).
This part of Ram is not cleared during a soft reboot. This is where
all the application data and state files are located (and any user
installed applications). So I suspect that geos (which would have typically
run in the startup routines) is what clears the state files.
Dom