Within a chat window, time stamps are only shown for new conversations or when a reply to a message is given. In cases where someone is sending several messages (e.g. over the whole day), the time stamp of the first (initiating) message is seen. This bad as if some message required an urgent reply or was time depending, I cannot know if I am too late or still in schedule. Even the chat log doesn't offer me the time of each message sent to me. Programs like pidgin show to each message a time stamp. I would therefore rate this as a critical feature.