I think I'm in this boat too. Getting the "HTTP error" with media uploads. I can upload a single image, I can upload multiple images below a certain size/dimensions (about 500px wide), but I can't upload multiple images of the size I usually use (610px wide). This causes many or most in that particular batch to stall and throws up multiple HTTP error notes.
Not sure if related, but I get a capacity error when I try to edit my large "functions.php" file through the WordPress editor. The rest of the PHPs, which are short, work fine.
Maybe a memory issue?