[PROBLEM] External HDD periodicaly disconnected and reconnected as RO

[towdie]

Hello,

I have problem with my external drive(Western Digital).

EDIT: Sorry Here is missing Info:

Software
XBian version:1.0Beta1.1
XBMC version:XBMC 12.2 Git:20130502-32b1a5e
Overclock settings: Xbian

Hardware
Power supply rating: 5V/1500mA
RPi model (model A/B 256mb/512mb): model B 512MB
SD card size and make/type: 8GB SanDisk Ultra SDHC Class10
Network (wireless or LAN): LAN(connected to TP-Link WR-1043ND)
Connected devices (TV, USB, network storage, etc.):
TV(Panasonic Viera TX-L32C10E) via HDMI,
HDD Western Digital Scorpi Black 500GB

Logile
Link to logfile(s):http://pastebin.com/kYxLU2Wx from dmesg | tail

Problem description:
HD is periodicaly unmounted and mounted for next available possition(from /dev/sda -> /dev/sdb ...) but only as ReadOnly.
When this happend I need to run mount -a to mount it back as RW.
The HD is formated to EXT3 and added in /etc/fstab for automatic mounting at boot.

How to reproduce:


Thank you