Tonight, I just happend to check my usage on the Sprint site and to my
surprise, I saw that I was being charged for overage minutes, when it
fact, I was well within my plan and have free nights and weekends.

The overage I saw was for today's (Saturday) usage.  I did a test call
and found that it not only showed up on the additional minutes, but
also went against my anytime minutes.

I called Sprint and they said I had been charged for the minutes.  They
credited my account for those charges.

Later, I tested again and the same thing happened.

I wonder if this is a system problem?  If so, some folks are going to
get a surprise when they get their bills.