Native Alarm Clock interrupted by push notifications

I have an iPhone 3 GS with the latest ( as of 3/1/2011 ) IOS installed. The Clock application has 3 alarms set to go of each Weekday, 15 minutes apart , using the default alarm sound. This is designed to make sure I get out of bed for work in the morning, even if snooze or "ok" the first alarm.

Environment:
My iPhone is plugged into the charger ( can't have it not wake me up due to dead batt)
Home Screen is in the foreground ( no apps open )
Screen is locked ( but not passcoded )
Alarms are set, the first one has snooze enabled, the 2nd and 3rd do not.

For the last 2 days, the 1st alarm goes off, I swipe to unlock the screen, the popup message disappears, and the alarm sound stops. Note that I am not given the option to snooze or acknowledge the alarm, as soon as I unlock the phone, the alarm turns off.

The next 2 alarms do not sound. If I fall back asleep ( like I usually do ), I wake up by myself, am late for work, and generally have a bad day.


Has anyone else seen this issue? I've tried a multitude of alarm clock programs, but I always come back to the native one since it's the most reliable. I literally own 3 alarm clocks but prefer the iPhone for that purpose.