What would be relevant code? The Buttons are the usual objects produced by a LOFT .gld file. Manually pressing newButton causes it to be drawn pressed and puts you into newButton_Click(). At the end of execution in the handler, can newButton be made to return to its released appearance to show processinghas finished? Default behavior when control returns to Win32::GUI::Dialog() is for newButton to remain pressed until another button is pushed.
Searches on the site and elsewhere have turned up little on the issue, www.mail-archive.com/perl-win32-gui-users@lists.sourceforge.net/msg00001.html being the sole mention; and there, '$button->SetState(1)' pertains to RadioButtons, not Buttons.