[SOLVED] Distorted sound in video and GUI sounds

[aitor]

Software
XBian version: 1.0RC3
XBMC version: 13.2
Overclock settings: default

Hardware
RPi model: B 512
SD card size and make/type: 8Gb
Network: Wireless
Connected devices: TV, USB HD.

Logile
Link to logfile(s): I can't find it.

Problem description:
After a new xbian install from scratch the sound seems to be OK in the first time, but turns distorted when I try to play any video.

Rpi is HDMI connected to TV.

I dont know where look for to solve it. Any idea?

Thank you very much.