Given the nature of the bug (and how early it shows up in the instance run start), I would be very surprised if it was imagecontent-specific. Maybe imagesize-specific, but even in that case I'd be surprised.
Maybe you tested a UEC image first, and it failed, then tried a eucalyptus one, and it worked ? In my testing, the DB recovered by itself after a couple minutes.
Given the nature of the bug (and how early it shows up in the instance run start), I would be very surprised if it was imagecontent- specific. Maybe imagesize-specific, but even in that case I'd be surprised.
Maybe you tested a UEC image first, and it failed, then tried a eucalyptus one, and it worked ? In my testing, the DB recovered by itself after a couple minutes.