Here is the problem: using SPD is easy to change properties to not allow users to close / minimize webparts from a wp zone:
Now how can we do that in code ? I have more then 30 aspx webpart pages on a site, I want to be able to do that so no one can change webparts properties (close, delete them etc.)
The only thing I did find is this link: spwebpartzonetools.
Reading more in SDK at: wss 3.0 sdk, at the second Important paragraph it says:
Although you can add Web Parts to the Display, Edit, and New forms for list items (DispForm.aspx, EditForm.aspx, and NewForm.aspx), doing so is not recommended or supported in Windows SharePoint Services. Adding Web Parts to list view pages (AllItems.aspx) is supported.
So that's my mistake that I want to fix :). I did break that rule. My problem can be fixed in SPD but I don't know if that can be fixed in code.
The mistake was "inspired" from one of the fabulous 40 Templates : BudgetingTrackingMultipleProjects.wsp. There on Projects list, on DispForm.aspx, Microsoft add more webparts to create a master-detail form.