Well, a few questions really...

While there is no set time that someone must respond to a box offer, what is the norm?  I have found that I've gotten replies to most offers I've made within 2 days, but have also had a few where it's gone weeks without a reply.

Also, is there a customary time frame for mailing books out in a box swap?  Most people I've boxed with have marked theirs mailed within 1 week, but I have one swap that's been accepted for over 1 week and while I've mailed my books, the other boxer hasn't even printed my address yet.  The person has all positive ratings, so I'm hopeful that they'll get mailed soon, but I'll be really upset if I don't get my books.  

I've had boxers wait more than a month before replying.  I also had one wait almost two months before she mailed the books.  Like you say, most respond within a couple of days and mail within a week.