I have tried this several times now. I have the plugin set to rebuild the sitemap manually.
Whenever I make changes to pages and/or posts I rebuild the map.
I noticed that sometimes the map does not rebuild even though the timestamp is updated.
Several days ago I made changes and manually rebuilt the map and it seemed to work.
Yesterday I changed 2 additional pages and rebuilt again and noticed that those changes do not reflect in the latest built.
After trying it several times I decided to download another plugin (RPS sitemap generator) just to see what happens. I rebuilt the map using that plugin and it reflect the latest changes.
Is there some cache or something else that must be deleted/cleared to rebuild the map. I just don't understand why this plugin does not work correctly.