Ebay Messages Problem

Here we go again. I’m trying to sell a stick of RAM and have been in contact with a potential buyer who seems interested in buying it. They’ve been asking questions about compatability etc and I responded to their first question but they’ve sent a second one which doesn’t show up in ‘My Messages’ on the ebay.ie site and I can neither respond directly from outlook or respond to the first question they sent as I’ve “Already responded”. If I can’t give the buyer the info they want, they’ll be off. Well done ebay.