What steps will reproduce the problem?
1. Start stock camera app
2. Take a photo
3. Change exposure to +2 (anything besides 0)
4. Take another photo
5. Observe that the photos have the same exposure
Other apps that attempt to set the exposure also do not work.
According to http://code.google.com/p/cyanogenmod/issues/detail?id=6696 this issue also affects d2vzw.
The attached logcat is for cm-10.0.0, but I can confirm the same problem in cm 10.1m1.