I have an HTC Inspire and I'm trying to use the new Google+ auto backup. All the photos say "Backup Failed". However, it is uploading the videos. I have checked every setting that I know of and it looks like it is setup right. Any ideas?
This method seems to work for me: Try deleting Google+ data/cache, then start Google+ app. It will log you in and then you can choose Auto Backup setting. You can then go to Sync settings, untick "Sync Google+ Auto Backup" and then tick it again. You can also go to the Google+ app settings and get it to upload all your photos/videos to start the sync.
Taking advice from this post: http://productforums.google.com/d/msg/google-plus-discuss/d3s4VKI3yWo/bq39QiqknWoJ
Another solution that worked for me was turning off Standard size in the Auto Backup settings altogether. When taking a new 8MP jpg using my camera and when Photo Size was set to Full Size in Google+, all the photos seem to be successfully uploading without error. This further confirms that the error is arising when Google+ is trying to convert larger jpgs to standard size.
I tried taking pictures at different resolutions, from 1.9MP - 8MP. 3.8MP and below uploaded without a problem. Anything with a higher resolution still failed.
So, the solution for now seems to be:
take pictures at a lower resolution
Change the Photo Size setting in Auto Backup from "Standard size" to "Full size"