mine did that. i removed the battery and waited a few minutes and threw it back in. It fixed the problem

give that a try and see what happens.

 

I have no idea why it did it either. I was getting really frustrated and thought my phone took a crap. Hasn't done it since though, so hopefully it was a one time thing.

 

This is a known bug with the phone. Supposedly it's a software issue. Last I checked Verizon is offering replacements for affected phones.

Mine did this once right after I got it, and again today. Not sure I'd wanna go get it replaced yet... especially if it's a software issue. Maybe someone else can offer some more in-depth insight.