Periodically the buttons will do strange things for some reason. (Possibly involving changes in the last vBulletin board upgrade?) I've found that there will at times be a longer delay in them showing up/responding when we have a newsletter going out.
Also I've noticed that you can't 'welcome' a lot of the long-time members, so I'm not sure if there is some pre-set cut off date for the welcome button to no longer be showing up?
Jordan will have more of an idea.
~ There'll be Chocolate, if God wills it. ~