So, i'm having the same problems as everyone else.
At first I got the http error when attempting to upload images. I went thru Otto42's fixes, reuploaded and replaced all files, restarted my browser, made an .htaccess file with given code, don't use badbusiness, etc etc. I use Firefox and I'm hosted on Laughing Squid. (Another thing, I just switched hosting, and thought I had backed up but all my posts are gone. I can live with that, tho.)
After I created the htaccess file, my error went from saying http error to "The uploaded file could not be moved to /var/www/vhosts/bowerbox.com/httpdocs/blog/wp-content/uploads. 102"
I've gone through all the various threads and tried unticking the months/dates folders box, typing or not typing the full path to the upload folder, and anything else I understood how to do.
I only know enough code to get myself into trouble, it seems, so I hope that someone can help me out or that a new release of 2.5 will fix this as images are pretty much the only thing I put on my blog!