It sure is nice to have friends in high places sometimes.
My sister was an assistant at the aforementioned conference. I poured my woes into her ear, and she turned around and emailed Carol Lynch Williams, who organized the conference, explaining what had happened and asking if anyone else had run into the same problem. Carol then emailed the editor, who responded that of course, I could go ahead and re-send it (but she recommended I add a note explaining what had happened).
So, the packet is off in the mail again today--hopefully it at least reaches its destination. I don't expect a positive reply, but since this is my first foray into querying (I don't count the rather embarrassing query I sent to Tor books when I was 19 and clueless and had just finished a 600 page single-spaced novel . . . ), it feels monumental somehow.
I'm also told that authors shouldn't expect to publish their first book (the learning curve is steep as you write and revise). So I'm trying not to get my hopes up too high. (Although a small part of me can't help wondering, doesn't that 600 pages count for something? Maybe that will up my odds). In any case, you'll know if something does eventually happen. That's hardly the kind of news I could keep to myself!