Help Phone vibrates randomly

[Kellsx90]

I was in the middle of typing out a text message when my cell phone (i5800) started vibrating (it's on silent and vibration is off). My phone froze completely, I couldn't even turn it off and it vibrated for a minute or two before I just took out the battery. I left it for a while and turned it back on. It seems fine now. Does anyone know what could have caused this?

 

[jahhus]

It's the phones way of saying ffs what are you doing to me, as it can be caused by badly written apps, I get that sometimes.

Mostly when trying new apps or with apps that are not compatible with phone or are just badly written.