Usb HDD changes port and resets

[toketin]

Hi, i'm using ArchArm under my Cubieboard and i have a problem with my powered hub usb and the external usb HDD, because i get a reset of it after some time of working, it changes the port from /dev/sda to /dev/sdb, and so it results no more usable for the service that uses it. It happens if i mount it manually with mount command and also by adding a line into fstab.
This is the error i get with dmesg:

$this->bbcode_second_pass_code('', '[ 166.050000] EXT4-fs (sda7): recovery complete
[ 166.070000] EXT4-fs (sda7): mounted filesystem with ordered data mode. Opts: (null)
[ 6292.930000] ehci_irq: port change detect
[ 6292.940000] hub 4-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
[ 6292.960000] usb 4-1: USB disconnect, device number 2
[ 6292.980000] usb 4-1.4: USB disconnect, device number 3
[ 6295.530000] usb 4-1: new high-speed USB device number 4 using sw-ehci')