Comment 12 for bug 139846

I repeated my tests just after I installed Intrepid. Here are my results:
1) echo 0 > /sys/class/rtc/rtc0/wakealarm
doesn't work due to Permission denied error

2) I found workaround :
username@comp:~$ sudo sh -c 'echo 0 > /sys/class/rtc/rtc0/wakealarm'
username@comp:~$ sudo sh -c 'echo `date "+%s" -d "+ 5 minutes"` > /sys/class/rtc/rtc0/wakealarm'
username@comp:~$ cat /sys/class/rtc/rtc0/wakealarm
username@comp:~$ cat /proc/driver/rtc
rtc_time : 23:20:51
rtc_date : 2009-01-21
alrm_time : 23:25:29
alrm_date : ****-**-21
alarm_IRQ : no
alrm_pending : no
24hr : yes
periodic_IRQ : no
update_IRQ : no
HPET_emulated : no
DST_enable : no
periodic_freq : 1024
batt_status : okay
username@comp:~$

It is interesting "cat /sys/class/rtc/rtc0/wakealarm" gives no output.

Computer didn't boot at specified time. Manual inspection of BIOS setting revealed correctly changed time (23:25:29). However date (of month) was wrong - 1.

3) I repeated step 2 with changed /etc/default/rcS file according to advice in http://www.mythtv.org/wiki/ACPI_Wakeup

Same result as in (2) in BIOS. Warning! I had serious problem to boot then! Finally, I had to boot using live CD and reject changes in /etc/default/rcS in order to boot again.

I am strongly interested to turn it working. So far without success. I am planning to test Fisslefink's solution next time.

Regards

Karel