VLC gets slow with video/audio files

[Mireyu]

Hi there, I'm having trouble using VLC while watching video in every format (mkv,avi etc) and listening files audio (mp3,flac).
VLC gets slower and there are huge gaps while playing, with whole seconds of silence during audio tracks playing and pixeling during video playing.
It looks like it hasn't enough RAM memory..Is someone having the same issues?
Videos and audios works fine with quick time.
I'm using VLC 1.0.1 and a macbook dual core duo with 2 GB of RAM, Leopard 10.5.8. and I've already tried a reset of preferences.
Thanx!