I'm having some problems with sounds. I can't hear any kind of sound when walking (althought I can hear a sound when jogging and moving while crouched). Also, are for walking through bushes? I mean, S.T.A.L.K.E.R. has those sounds, I find it strange if SRP doesn't. I have installed the sound patch from the downloads and all, so yeah...
Source engine or Nexus script issue, although it might even depend on surface's material. There's no fix this.