BB Pearl :: No Browser Icon On 8100?

In 2009 my husband bought me a brand new Blackberry Pearl 8100 from the internet (he can't remember exactly where from). I put my existing O2 sim in it, expecting to be able to access the internet/emails, but neither were available to me. A quick call to O2 cleared that one up - my sim was Pay & Go and at that time, O2 were not doing Blackberry web & email on Pay & Go. I used it as a phone for a bit, got peeved (wanted internet and emails!) and bought a Samsung Tocco lite which I have been using up until last week when I found out that, since last July, O2 were now doing Blackberry internet on Pay & Go. So, I excitedly purchase a bolt on from O2, shove my sim in my lovely Blackberry Pearl, get excited when I see the new icons for Facebook and Google etc... and then I realise that there is no browser option. No globe icon, nothing. The only way I can see a browser icon is if I press the menu key and select 'Switch Application'. The 'phone then says 'requesting', then offers me an option to sign up for Yahoo Messenger. If I hit the 'back' button, the screen goes blank. If I accept 'download', I get: 'Sorry, your device does not meet the system requirements that are needed to support Yahoo'.

I have set up my emails and they work fine. If I click on links in emails, I just get a blank screen.

I have spoken to O2 who have said that 'everything is fine their end' and there is no reason why I can't find a browser icon. They told me to check out the latest Blackberry download so my 'phone is updated. So, I have installed what I believe to be the latest version but that has had no effect whatsoever.

A battery pull (well, about a hundred of them actually..) has also had no effect).