To verify this issue follow the steps
1.create a table in database
2.after creating open the forms in design view
3.then insert a textbox(1) and assign data to text box from tables
4.after assigning data to text box, insert a check box and connect check box  to textbox(1)
5.then switch off the design mode and click on the checkbox then  it displays the given data
6.when we uncheck  and again check the check box it does not displays the given data. (sometimes)