If you define all forms in the desktop this will happen.
If you define a main form in the desktop, and than all other forms as modal and show in toplevel form/alwaysontop, they will stay modal.

so the order is than

do form mainform (modeless and in desktop)
read events
-------other forms (started inside mainform in toplevelform and modal/alwaysontop)

if you want more 'mainforms', start them from the mainform start the next one
and release the mainform

keep all 'childforms' in the modeless forms

rgds,

Albert