all depends on your photo size Rob. If your uploading a large file it will take longer than a smaller file has nothing to do with category.
Uploading multiple files and it hanging is a server timeout issue either by memory issues or timeout. That can be corrected by correctly editing your servers php settings through the php.ini file to allow for larger files to upload.
I hope that helps your upload thing.
By the way I looked at your email you sent and it has nothing to do with speed or adm-misc.php changes persay. You where not able to use the photopost backup utility to backup the database no big deal it does not work on every server. As mysql needs to be on the same server as Photopost and we need explicit permission to use mysqldump. Not every server is setup like this and quite frankly as big as your databases are you should be using dedicated programs to backup and tar your databases and files and ftp them somewhere safe.