For a couple weeks now, I was having a problem both with scheduled posts and other post updates not regenerating the homepage, and not clearing the cache on new posts on some of my sites. I have temporarily resolved it after working with the debug flag set and adding in some additional checks, but it's a kludge so I'm hoping this may help donncha.
In 1.1 the supercache directories are created from $_SERVER['SERVER_NAME'], however in get_supercache_dir you get the directory to clear from the 'home' option. In every case I had a problem with, the 'home' entry began with 'www.' and the $_SERVER['SERVER_NAME'] did not. Hence, following the publishing of a post it was trying to clear index.html or whatever from cache/supercache/www.abc.com instead of cache/supercache/abc.com which was the directory actually on the disk.
It looks as if you need to change get_supercache_dir to reflect the usage of $_SERVER['SERVER_NAME'], although since the blog_id is a parameter you can't just use it directly of course. I suspect this is causing other side effects for people with various settings. (It sure drove me crazy!)