I have a serious problem with my iPhone 4 (cocoa error 640). Any help?

I'm dealing with a problem on my iPhone 4 for about 4 months. There's a thing going on with my apps' connection with my camera roll. Even though I have enabled the access of apps such twitter, instagram e.t.c in my camera roll, every time i use them it says that this app doesn't have access in my... show more I'm dealing with a problem on my iPhone 4 for about 4 months.
There's a thing going on with my apps' connection with my camera roll. Even though I have enabled the access of apps such twitter, instagram e.t.c in my camera roll, every time i use them it says that this app doesn't have access in my photos.
Also, i cannot view people's profile pictures on twitter via the app because every time i tap them i get a note that says "Cocoa error 640".
Plus that the devise doesn't allow me to send text messages (neither sms or iMessage).
I've talked about it with friends who own an iPhone but non of them had the same problem. I've tried restoring the device and starting all over again as a new iPhone. It does solve the problem but it's temporary. I believed with the iOS 7 update everything would go back to normal, but I started having that problem again earlier today. Now I can only use my phone for music and phone calls (which i rarely do) so my phone is now rather useless.
Any help?? I'd really appreciate it, this error is really getting me frustrated, i've searched the web for any solutions but i only found some tutorials that require the knowledge of Objective-C which is a programming language i cannot understand.
Thank you
3 answers 3