after another attempt, it seems that proftpd process has FIFO open to frontend, which prevents the frontend from finishing. new process numbers here:
root 2182 0.0 0.2 57600 17380 pts/1 S+ 16:13 0:00 /usr/bin/perl -w /usr/share/debconf/frontend /var/lib/dpkg/info/proftpd-basic.postinst configure root 2187 0.0 0.0 0 0 pts/1 Z+ 16:13 0:00 [proftpd-basic.p] <defunct> proftpd 2272 0.0 0.0 124704 3788 ? Ss 16:13 0:00 proftpd: (accepting connections) # lsof -n -P |grep 16675 frontend 2182 root 8r FIFO 0,10 0t0 16675 pipe proftpd 2272 proftpd 3w FIFO 0,10 0t0 16675 pipe -- Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. M$ Win's are shit, do not use it !