I modified the log out script slightly. Try it out and see if it makes a difference.
Also, when you wind up logged in as "deleted" and close all instances of IE and look at your cookie, is comic_user set to 'deleted'?
Some other things:
1. Make sure that when you delete your Stripcreator cookie that you close all instances of IE first. If you delete it while IE is still running, it will just write another one to the disk.
2. Try clearing your cache. I don't know why this fixes so many problems but it seems to.