There is some discussion in the forum on the use of the simple checkbox on a tabular form but no solution that I can make work.
If I put a very simple example on apex.oracle.com of a tabular form using the wizard with 3 fields in a table and 'Select one, two, three from table' with field three set as a simple checkbox and submit it, all is fine. By entering Y,N in the 'List of Values Definiton', clicking the box on the form puts a Y in the table and no errors result.
If I do the same thing on the earlier version 4.0.2 and submit it I get the error "The requested URL /prdapex/wwv_flow.accept was not found." We cannot update to 4.2 for several months. Is there a way to make simple checkbox work in 4.0.2?
It worked fine in 4.1 from which apex came with tabular form enhancement. In 4.0, you can create manual tabular form. Please see http://deneskubicek.blogspot.in/2008/04/manual-tabular-form.html. (The credit must go to Denes Kubicek :) ).