Media player problem. Memory card not recognised problem.

I'm a proud user of 6120 classic, and had this phone for about a month now.

Recently I was trying to access the media player from the menu, but it just would not start. Well it started, but it would not show me the menu window or whatever you call it. So I went back to standby mode and tried to close the media player by pressing and holding the menu button then pressing c, but the media player just would not close.

However when I opened my sound files from the gallery, the player automatically started and was working fine.
The thing is, when I used the menu button (by pressing and holding it), I saw I had 2 media players (of the same programme) opened - one from trying to open it from the menu, and the other from opening it from the sound files in my gallery.

The problem persisted even after I switched off and on my phone and tried the above again.

This was not really affecting me until today, when I was trying to open the camera, the phone hung on me for the first time. All I could see was the wallpaper of the phone, and pressing the red button or the switch off button didn't help so I had no choice but to remove the battery directly.

So I was wondering if there's something wrong? I don't think it's due to any virus as it's been a long while since I transferred programmes to my phone before the media problem started.

Also, whenever I switched on and off my phone, my phone seems to be unable to recognise my memory card until I removed and put it back in again.

So any takers?
Thanks for your time.