xlsclients
ajudará você a descobrir qual processo possui o pop-up. De man xlsclients
(na verdade, de link ):
fiel (1) xlsclients.1.gz Fornecido por: x11-utils_7.7 + 1_i386 bug
NAME
xlsclients - list client applications running on a display
SINOPSE
xlsclients [-display displayname] [-a] [-l] [-m maxcmdlen]
DESCRIÇÃO
Xlsclients is a utility for listing information about the client
applications running on a display. It may be used to generate scripts
representing a snapshot of the user's current session.
NAME
xlsclients - list client applications running on a display
SYNOPSIS
xlsclients [-display displayname] [-a] [-l] [-m maxcmdlen]