Joao,
Assume you have a view named MyView that updates a table named MyTable. Both are in the DE and both are buffered.
At the start both the view and the table are clean (that is no pending changes in them for updating). You make a change to the view. Now the view is dirty and it needs to be updated to write its changes. You TableUpdate the view which writes changes to MyTable (which is buffered and is now dirty, with pending changes).
In the above scenario you have updated the view but that caused the table to become dirty and you have not updated the table yet. When you close the form VFP will resolve the situation.
This situation is called double buffering, as the view is buffered and so is the table. If you must have the table in the DE and buffered, then you must TableUpdate the table after you do the view.