The control source for each control is a field in a cursor.
When I access my form and try to modify any of the columns (edit box or text boxes) it says this control is read only but when I exit the form and come back into the form (without closing the app) I can modify the contents.

Are the ControlSources for the columns specified in the form Alias.Field or are they specified as only the field name. If the latter is true, using Alias.Field should solve your problem.