Not all Post Authors showing in Sidebar

Not all my auth开发者_开发知识库ors are being displayed in sidebar widget. One in particular has multiple published blog posts.

The problem arisen when a database was backed-up and restored on another server. Both databases, and code should be identical.

Its the standard authors widget that comes with wordpress.

Have you tried removing the widget completely (not saving it in inactive) and then re-adding it?