That doesn't sound possible. It sounds like you have another table occurrence in your relationship graph based on this same table. You have to have at least one in order to use a layout to display this data. (Perhaps you added it back before creating the layout.)
I suggest opening Manage | Database | Relationships and selecting the table occurrence that you have specified for this table. Then click the "select tables" button just to the left of the percent magnification box and choose "Select tables with same source table" to see every occurrence with the same data source table highlight.