What is wrong with my camera? Card issues?

I have a Nikon D70. All the sudden the card starts malfunctioning and the little icon [FOR] or [CHA] shows up. Yes, I have formatted the card using the camera and my computer before using the card each time. And just when I think it starts working right, I take around 200 pictures and the computer says "This card needs to be formatted before use… " I put the card back in the camera and the pictures show up just fine. And I try again repeatedly and then all of the sudden when I try to view the pictures on the camera, the screen on the camera says "FILE Can't BE VIEWED" or something along those lines. I did a ton of research and found out that I need a new card.

So I bought a new card about a month ago. Everything was just fine until today. THE SAME EXACT THING HAPPENED. I took like 175 pictures… GONE… Goodbye.
"Oh, card needs to be formatted"
Well, I did that before i took the pics.
" oh everything shows up fine on the camera!"
OK, go back to the computer and try again." Card needs to be formatted."
Go back to view on camera. "File can't be found."
Only like 3 pictures show up. And I can't even put the stupid things on the computer and they're blurry anyways.

Please help me.

Added (1). The new card I bought is a Lexar Platinum II 4GB 200x. The card I had before was a Lexar also. Both have the same exact problems. I'm not going to waste my money on a card if it's not going to fix anything. Should I just take my camera in and get it fixed? Or buy a new one because it's out dated anyways. I bought the camera in around 2005

Added (2). * To Hondo. I'm sorry, when I was typing this I hadn't read your answer yet. Thank you for your answer though. I'm sorry I seemed rude. Happy New Year

The problem is that your computer and camera use two different methods of formatting your memory card. If you format the card in your computer, your camera will have problems, and if you format it with your camera, your computer might be having problems (although the second possibility is less likely). ONLY use your camera to format the memory cards used by your camera. When you transfer your photos to your computer, use a memory card reader attached to the computer, and just copy the files over. Once saved to your computer, your computer will be using the formatting it understands on its own hard drive, and should not have any problems opening the photo files.

I guess you didn't read my answer as I did not tell you to buy a new card. I told you to format your card in your camera, and never with your computer. See if that fixes the problem before you spend money on a new camera.

OK.

See if you can get the card reader eliminates as the cause of your problems.

Memory cards should always be formatted in camera.

Having said that, this does sound a bit like a D70 on it's last legs. Fixing it will cost most likely at least as much as a used d80 would and that's already quite a step up from the d70.