Actually the issue is persisting for me in Beta 6, even with a complete wipe and restore. I need a method that will allow me to force the camera app to rebuild my photo library database from scratch because it doesn't seem this problem is going to fix itself in this beta, at least not for me.
I had the same problem. Below seemed to solve it for me.
--WARNING--
If you're not comfortable modifying system files/folders on the phone do not proceed. I'm not an iOS expert so if you brick your phone following these directions don't look to me for help. I just did some research and figured that by doing this it would force the entire photo library to essentially start from scratch. If you have photos on your iPhone that you are afraid of losing I assume you would be able to take them from the DCIM backup directory (step 3), import them into iPhoto and then bring them back into your iPhone via sync after completing the steps below. Don't hold me to that though.
1> Grab iPhoneExplorer (so you can browse the filesystem)
2> Force quit the Photos & Camera apps (may not be necessary)
3> Browse to the Media folder on the filesystem (via iPhoneExplorer) and drag the contents of DCIM and PhotoData to a folder on your computer to back them up
4> Delete the contents of DCIM
5> Delete the contents of PhotoData
6> Launch Camera app and take a picture
7> Launch Photos app and confirm the Camera Roll is working properly
This also seemed to resolve the annoying errors that always said it was syncing, restoring, etc while viewing the camera roll and other albums.