Device or resource busy

Hello everyone!

My info: Ubuntu feisty (AMD64), kernel 2.6.20-16-generic, hdparm 6.9-1ubuntu2

Long time ago, my linux used to hang (or freeze) randomly when entering to X.
I figured out that my HDD tunning settings were causing this problem.
Now, I run it manually, but I still have random hangs (but less than before).
This is the script I run:

Code:

hdparm -d1 -X udma2 -u1 -k1 -c1 /dev/hda hdparm -d1 -X udma2 -u1 -k1 -c1 /dev/hdb

This settings I copied once from a forum and worked with me very good (besides the hangs).

The error message that I receive sometimes is:
HDIO_SET_UNMASKINTK failed Device or resource busy
...
HDIO_SET_KEEPSETTINGS failed Device or resource busy

And after that, I'm not able to run any command. It is like when the computer freeze but with the difference that I'm able to move windows inside my screen (of course, I can move my mouse pointer) and even to shutdown X and I can still write anything in the console, but when I execute a command (any command) it do nothing and I can't unblock it. So I have to had-reset my box.

I don't know if it is related, but some time ago, my /dev/hdb showed sometimes "SMART" errors, when turning on the computer and I run once "smartctl" and displayed that in less than 24hrs my HDD was going to fail badly (more than 2 months have passed now). I cleaned my computer from inside and I change the HDD position from horizontal to vertical and after a while I didn't receive more "SMART" errors and if I run "smartctl" it displays that everything is fine. I think it may be related to this, but my HDD seems to work without any problem without running my hdparm script (unfortunately, without it, everything slows down).

Any Ideas? anyone know why I'm getting those errors? I wonder if my settings are correct...

Thank you for your time in advance.