I have Ubuntu 14.04 64-bit running vlc 2.1.4, using unity desktop and xscreensaver installed from the Software Center. (Gnome screen-saver is not installed.)
Whenever I play a video in fullscreen in vlc the screensaver comes on. I have the option inhibit the power management daemon during playback checked and disable screesaver checked, but the screensaver still comes on. I upgraded from 13.10 64-bit Ubuntu and uninstalled vlc and reinstalled it but the screensaver still comes on.
I reset my vlc config file by deleting it and starting vlc again to recreate.
Linux / Unix: $(HOME)/.config/vlc/vlcrc (v0.9.0 and above),