Hello,
it's hard to say,where the problem is. In this case we need to see the code to find out the source of the problem.
Regarding the 4.0 version, there is possibility to use atlernative forms, so you don't have to customize your code, you just create appropriate alternative form using our UI.
To find out more about alternative forms please read following article from our develoeper's guide(
Creating alternative forms)
Best Regards,
Zbysek Nemec