I think I should try and specify more what the issue is:

There is a database that contains only the tables / data.

There is an interface (copy) on multiple computers that allow interactions with this database. So, many users are adding entries to a specific table.

There is a report that summarizes some of the data in this table.

Is it possible that the data being added to the table IS actually added, but if you open the table, it cannot be seen (though sometimes it can be?!?). Is there some property that exists that can be causing this strange occurrence?!?

For example, I know that you can have a filter on a table, that might show everything except the data for one user, but is there a property that can be set within the table structure that could also cause this?

Let's say that the table has fields like UserName, Date, TimeIn, TimeOut.

Everyone uses a form to enter the time they worked wach day.

If someone else opens the table, they see everyone's times for every day, except mine - after a certain date (they can see my times, but only up until, say, last week)!

If I open the table MYSELF, I see everyone's times for every day, INCLUDING ALL my own times (up to the present)!!!???!!!

Is there some setting that would allow for this to be happening, and what would that setting be

When you close a table that has been filtered, you are asked if you want to save. If you answer yes, the filter is saved. you can tell that a table is filtered because at the bottom of the window, you will see the word "filtered" next to the navigation bar. Click the remove filter tool on the toolbar to remove the filter. The filter can be different for each person as long as they have their own copy of the FE.