Just thought I would pass this tidbit along because it took me quite a while to figure it out.
My NT 4 application had a few parent forms with browses of child records. To support multiple selection of children records, I used a button to call another form which processed the tagged records. The button used a URL to call the relevant form with its parameters. Worked fine.
I moved the app over to NT5 (or it may have been a later release of NT5), and found the parent records were not updated or changed when I clicked Save after adding child records. The problem was the button 'Type' . The original type was 'Button'; it now has to be 'Submit'. Otherwise the parent form never gets the Validate and Post stage parameters.