If the form has its popup property set to true then it will stay on top of
everything else that is not also a popup. If the form must be a popup then you
will need to close or or hide it when the report is opened.
IIRC, in A2002 and A2003, Reports also have the PopUp Property and if set to
True / Yes, the OpenReport method will pop up the Report on top of the PopUp
Form.
I did a quick test in A2003 and it seems to work correctly.