The navigation portlet shows the items with the order they have in the corresponding folder. So if your news items are ordered alphabetically, they will show up so. The news portlet, available by default in the right portlet column, sorts the news items by data, newest on top. This behavior is hardcoded, to change it you need to replace that portlet with a collection portlet, as @espenmn already pointed out.
To re-arrange the content of your news items folder, you can navigate to the folder contents and then click on the Rearrange button, and choose Publication data and check Reverse:
This will permanently re-sort your items the way you want them.
New items will always be added on top, so you will only have to do this once.
I saw your other post about your upgrade, maybe that "destroyed" your original sort order.