interesting issue with phone on vibrate

[k3m1c6]

So while I'm at work I keep my phone on vibrate. But for some reason, if I take or make a call, after I hang up, the sound is turned on every time and I have to put it back on vibrate.

Anyone have an idea why this is happening?

I'm on Verizon if that matters.

 

[BuckyBadg]

When you pick up and use the phone, could you be pressing the volume-up button without knowing? The phone is great, but there are poor design aspects, another being the volume controls directly opposite the on button.

 

[k3m1c6]

Thanks for repling. I considered that so I was vary careful not to hit the button and it still switched.