I'm using hudson 1.306 but this has been happening in at least 1.297 version as
well.

In Hudson's global configuration, I removed the previously entered values for
Hudson URL for Email notification and Extended Email Notification and saved the
config page. But when I went back to check, the values were still there.

Worse, the value for the Name of my Public Hudson Server in the Build Publishing
section now was changed to the name of one of the other plugins that I
installed: sidebar.

I tried several times, un-installed the sidebar plugin, repeated the above steps
again. The values for Hudson URL still stayed but the name of my Public Hudson
Server was changed to yet another plugin: audit-trail.

Now my build publishing is broken as the name of the Public Hudson Server no
longer matches those in my jobs. I cannot change the name back to what it
should be. Updates to global hudson configuration simply do not take.