I recently had that problem saying "Could not start camera. Close other applications and try again" and i Finally fixed it temporarily.
It worked for like 1 picture, and then the color just completely exploded. The camera is only picking up 2-3 colors...green and pinkish purple.
Here is a picture of a picture i took with the camera: ImageShack - Hosting :: img00013pj7.jpg
Also, when i open the camera, it takes about 30 seconds for the "rainbow colors" to appear. And after taking the crappy picture, it's like the phone turns off for a couple seconds, and then comes back to life showing the picture. (Just thought i'd mention this)
If anybody is wondering how i fixed that camera problem, heres what i did:
1. Go to Options
2. Go to Advanced Options
3. Go to Host Routing Table
4. Click the menu button. (dots)
5. Click register now.
- It should send you a message.
6. Do a battery pull.