The code is:
--------
sub some_sub {

$results = shift;
#some code...
GT::Plugins->action ( STOP );
Links::SiteHTML::display('my_template', $results);
return;
}
--------
If I return $results - it displays both my_template.html and modify_success.html. If I don't return anything - it gives me the error - which is understood, since modify.cgi ( _modify() in particular) expects hash in return. Now, obviously I will have to make a separate hook on 'site_html_modify_success' and try to handle it there...
I hope this was descriptive. If not, let me know, and I will try to give more details.

Thanks,

Masamoda :)