Thank you Sandra. I think I always do "accept" the request, in addition to sending a message to the guest. But perhaps I have skipped that step once or twice. It occurred to me that maybe another factor is causing the problem: I am listed as the Host, but the payouts from the guests go into my husband's PayPal account, because he was listed as the original host when we first opened our guest house. Last year, we changed it to me, since he really doesn't like using the computer very much, and I take care of all the booking and communication responsibilities. But maybe some of the extra reminders from Airbnb are actually addressed to him, and some to me, because both our names are on the account. And because of his aversion to the computer, all email addressed to him is automatically forwarded to me, so I get them all. H-m-m-m. We'll have to fix that! But I will be more careful in the future to always "Accept" before anything else. Thanks for your help!