Did you by chance install snapture.. I just recently found the solution.. Here is the solution froma nother thread I answered in..
"Ok got the answer.. found in another forum but done my way.. Ok so I use winSCP with ssh to get into the iphone files..you could also used Finder if you have that..
browse to the folder: /private/var/mobile/Media/DCIM/
Delete the folder called 100Apple..
Then take a picture using the original camera.. I found it works best to leave your first picture in your photos with a picture from the original camera..
Now my original camera works.. Snapture works.. and I can save images from the internet again."
Sorry, thanks for the help, I've been busy, still have the problem..
Ok, the first program I got from Cydia was Snapture, I tried deleteing it to see if that would correct the problem but it did not. I don't know how to use SSH, don't know what winSCP is, but I did download Finder from Cydia, although I couldn't figure it out, lots of options and files, and I don't want to delete the wrong thing.
Is there a step by step guide somewhere of how to fix it using Finder?