If you try going to this page and it's slow to load, or you get an error, "Lost network connection," it's because so many more lists have been added to the system. At this point, the page may be so slow that the web browser gives up before the page finishes.
Alternatively, you can go directly to your list.
http://mailman.mit.edu/mailman/listinfo/_LISTNAME_ (where LISTNAME is the name of your list)
http://mailman.mit.edu/mailman/admin/_LISTNAME_ (where LISTNAME is the name of your list)