Orange SPV E650/HTC S710 - Constantly vibrating?

[Guest Rhizzyrhiz]

I wonder if anyone can help me figure out what to do about my phone...

If it's at a weird angle/not been used for an hour or so, when I start to use it it seizes up - then, both lights at the top (red and blue) light up and the phone starts to constantly vibrate until I disconnect the battery.

Has anyone else had this problem, and if so, is it fixable? It's not insured and I've had it since November. It's been doing this since January.

Many thanks for any help! :D