Why are my 1st and 2nd calendar alerts swapping?

I searched the forum but didn't see any answers to my calendar alkert issue.

For quite some time now, periodically, my 1st and 2nd calendar alerts have been swapping places and I end up getting no alert at all.

When I create a calendar event and set the 1st alert, at say 2 hours before, the set the 2nd alert at say, 1 hour before, at some point they swap places. The "1 hour before" alert becomes the 1st alert, and the "2 hours before" alert becomes the 2nd alert. When this happens, I usuually get no alert tone at all.

I have actually seen this happen. I've created an event, set the alerts, pressed "done," and as I was reviewing the new event, the alerts have swapped right in front of my eyes, as I'm reading it. So far, if I catch the swap, and fix it, the alerts seem to stay as I correct/re-set them.

Anybody have any clue as to what is causing this, or how I can fix it?

Thanks,

BerkRider