Sorry for the delayed reply.
Here is the commandline output for vlc :
VLC media player 1.1.13 The Luggage (revision exported)
Blocked: call to unsetenv("DBUS_ACTIVATION_ADDRESS")
Blocked: call to unsetenv("DBUS_ACTIVATION_BUS_TYPE")
[0x871c914] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
Blocked: call to setlocale(6, "")
Blocked: call to setlocale(6, "")
Blocked: call to putenv("LANGUAGE=en_US.UTF-8:en_US:en")
kfilemodule(13184) KSambaSharePrivate::testparmParamValue: We got some errors while running testparm "Load smb config files from /etc/samba/smb.conf
Loaded services file OK.
Warning: Service printers defines a print command, but rameter is ignored when using CUPS libraries.
"
ALSA lib pcm_dmix.c:1018:(snd_pcm_dmix_open) unable to open slave
[0x87e4e7c] pulse audio output error: cannot connect to server: Connection refused
Cannot connect to server socket err = No such file or directory
Cannot connect to server socket
jack server is not running or cannot be started
[0x87e4e7c] jack audio output error: failed to connect to JACK server
[0x87e4e7c] oss audio output error: cannot open audio device (/dev/dsp)
ALSA lib pcm_dmix.c:1018:(snd_pcm_dmix_open) unable to open slave
Segmentation fault
There does not seem to be anything related to screen dimming as such. There is a problem with audio however.