[PROBLEM] HDD wakes up himself after some time

[feg]

Unfortunately this tool isn't for my hdd http://support.wd.com/product/download.asp?groupid=304&sid=17&lang=en

So I probably can't disable built-in sleep mode.

But, this is the way how to work around the problem but it didn't solve issue, because your and my hdd should work propertly with built-in sleep mode. If drive is working properly on Windows, issue is on the side of XBian and not hdd.