Hi!
I have a tricky problem.
My computer is dual-boot OpenSuse_11.0/M$ WinXp, and the problem is when I shut it down (poweroff) from Linux - the next morning it turns on at 6 a.m. though the BIOS RTC Alarm feature and APM are turned off (however the alarm time in BIOS is set to 6a.m. but the alarm itself is OFF)
Next, when I shut it down from WinXP - it stays off until I push the Power button.
As far as I can conclude the problem is in linux kernel module (apm,acpi,rtc or something else I don't know of) or I am wrong, but I have no idea how to fix it. Most of the search results are exactly the oppposite - people desire to know how to transform a computer into an alarm clock

You could try booting Linux with no acpi/apm support. Just add the following to your boot command.
It could be the other way around. I'm not using my usual computer so I don't have my web book mark for the boot command parameters.

I did the thing, booting with noacpi, noapm...nothing worked.
Besides, I'm not interested in turning OFF the ACPI, I'm interested in its proper configuration that suits my needs, for example, if it can wake up using RTC_CMOS then, I'd like it to be only for weekends, or the other way -- only for working days...
I wish to know the precise place to configure the RTC alarm, because in BIOS it is a;ready DISABLED, hence, this has to be some sort of config file or something...