Nokia :: E51- Received A Text - When I Went To Open It The Phone Just Froze

I've had a few problems with my Nokia E51. I got the phone from my uncle who didn't like it after initially buying it. He bought it for O2 but I'm with Vodafone.

Anyways I got the phone unlocked and put my vodafone sim in and it worked fine. I changed the settings around on wap as well so it goes to vodafones homepage instead of o2's and it was working grand.

Then problems started with it. Firstly, I received a text one day and when i went to open it the phone just froze. It wouldnt let me look at the text and every button i pressed didnt do anything. The screen just stayed the same.
I tried turning off and on and taking battery out but everytime i turned it back on the text would appear 'one new text message' and the phone would still be frozen.

After a few months I tried the phone again and it was working fine. I had it for about a week again but then another problem surfaced. I looked at the phone randomly and the screen was flicking between differents screens. It was as if i was pressing loads of buttons but i wasnt pressing any! It was just flicking between screens really fast. I turned it off and back on, then battery out but kept doing the same when i turned it back on.

I left it for a month again and last night I tried turning it on and its working fine again. I know its gonna start up again though so I wondered if there's something I can do while it's working to stop it from breaking again. Is there a virus in the phone or something or is it just a bad batch?