404 page not found error after upgrade to 4.0 from 3.x

Question

We developed this application in 1.6 and a couple years ago upgraded to 3.2. We've just upgraded the Production version to 4.0.0 (that's what was on the Dev box). I understand that the template we used when developing it is now obsolete and I added some stuff to make it work properly (found tips here). In Dev it seemed to work correctly but now that it's in production we're getting a 404 Page not found error which "seems" to only occur after a search returns some results and you change the search criteria and try to rerun the search with this modified criteria without first leaving that page (if you click to a different tab and back before changing the search criteria you don't get the error). It doesn't matter which criteria field you change (date, text, LOV) the error comes up consistently. The criteria is submitted via a button (Go request). It's a PL/SQL function body returning SQL query. The only processes that are run is a Reset Pagination on the Go request.
Is there some quick setting that can be changed that causes this? Or something in 4.0 that is different that I need to change when submitting a page, etc... I can't see anything in the debug & all the variables do have appropriate values.

Answer 1

A column in the search results was changed to a Simple Checkbox when we upgraded to 4.0 (it has always been a checkbox in the older APEX versions). When I put it back to Standard Report Column I no longer get the page not found error.
Is there some additional/different setting I need to do in order to use the simple checkbox option in a search results set?
ETA: I see now that Checkboxes are not intended to work in standard report regions so I'll change them to LOVs or something and my problem should be solved.
Edited by: mimi_jones on Jul 18, 2011 6:16 AM