Just a “ditto” here on this issue. We’re running a production site at 1.6.3 and a dev site under 1.6.4. We SuperAdmins can upload anything under 1.6.4 but any other user group has about a 50/50 success rate with JPEG images processed either through PS or Fireworks.
The same users in the same Member Group on the production server running 1.6.3 don’t have any problems with the same images that failed on 1.6.4.
This is good to know so we don’t upgrade the production site to 1.6.4.