Alarm Expires earlier than intended when using set

问题:

1) Sample was used for repeating alarm.
2) setInexactRepeating(60000,60000), first one expires happens at 20 to 30 secs, rest ones expires in time i.e 60secs.
3) setInexactRepeating(1000 * 60 * 25,1000 * 60 * 25), first one expires happens at 10 to 14 mins~, rest ones expires in time i.e 25mins.
4) Docs says "Your alarm's first trigger will not be before the requested time".

Anyone experienced this before?using setExact/set and restart the alarm works well and setRepeating has problem too!