After discovering this issue, I sent a message to Cloudmark. Today, they came out with Ver 1.8 (I wa

After discovering this issue, I sent a message to Cloudmark. Today, they came out with Ver 1.8 (I was running Ver 1.7). Removing Ver 1.7 and installing Ver 1.8 resolved the problem - messages are now being marked read as soon as I move to them, including the last unread message.