just one thing I noticed (nothing to do with the sandboxing issue), since 454, the progress bar for manual scans really takes a while before showing anything. The scans run, absolutely normally, but the progress bar (percentage number as well as yellow progression) is really late when it starts. For instance, I got a scan running for 3 minutes now, and the bar is empty/idle.
And when it finally starts showing something, it's not accurate at all (percentage is wrong)... it finally catches up with the actual stand of the scan when half of it is done.
edit: example on screen shot after about 40 secs...