Depending on the properties of the checkboxes, they could move or resize when a row or column is hidden. Right-click on a chekbox and select Format Control. On the Properties tab, play with the Object Positioning properties to see if that has any affect.
Alternatively, your button that shows the hidden cell could also set the checkbox's properties e.g.;
Sheets("Sheet1").CheckBoxes("Check Box 1").Visible = True