Irritating fault

Yesterday this light came on on my phone. It's never been on in 6 years. It wont go off (tried turning it off and on, taking the battery out etc). It's draining the battery within 12 hours which is a pain as I used to only charge it once a week. This is very very annoying. Any ideas blippers?

In other news, last day at work until 2013 today! Woohoo.