BB Pearl 8100 :: 8120 - Crashing Can Happen At Any Time - Not Showing Recent Call List

I've had my Pearl 8120 for about a year or so and for the past 8 months or so it's been unexpectedly crashing, not so much at first, but it has gradually got worse to the point where the phone has become practically unusable, crashing almost every 5-10 mins. The crashing can happen at any time, whilst on a call, texting, emailing, web browsing, menu browsing etc.

Here's what happens:

The screen suddenly goes black, and the red light at the top lights up, then the screen lights up and I get a turning hourglass. This will remain on the screen for anywhere from 30 seconds to 5 minutes, during which I cannot do anything (turn it off, even taking the battery out doesn't fix it, as it returns to doing it when I put the battery back in). When it's done doing this, my home screen appears, giving me a message reading "Verifying Security Software", a loading bar which loads up to 100%. After this, I can use the phone (until it crashes again!), but it doesn't have the memory of the previous call (in other words, it doesn't show up in my recent call list, nor does it remember who the last person I called was in my address book), and I lose whatever txt/email I was typing. I thought it might be a faulty battery so I bought a brand new battery but still the same problem.

This crashing seems to be entirely random and I know I'm not accidentally pressing anything to cause it. There are days where it happens every few hours, but there are some days where its every 5 mins!My phone seems to have moods!

I feel like throwing my phone against a wall and watching as it smashes into a million pieces does that explain how I feel?