Worldox lists are dynamic, constantly changing. The more people use Worldox at your site, the more likely it is that worklists could change while you are viewing them.
That is especially true for very active client files in shared, workgroup environments. In the five minutes since you last opened a worklist, other users could well have added files, deleted files, checked documents out or back in.
That is why it's good practice to refresh (synchronize) visible worklists. If you cannot find a document where you expect it, try clicking Refresh in the Worldox toolbar. The currently-visible worklist then reloads. Any items added, deleted or changed since you opened the worklist should now be there.
Note: Refreshing worklists is an ad hoc, on-demand process - somewhat different than the automatic file synchronization Worldox uses to check for checked-out, checked-in document changes on program start-up.