Hiya! The messages that I'VE read are a different colour...making it easy to see the ones I havent' read. Are you logged in and have you bookmarked the 'all forums' page under your login name, making this happen on your computer too? (weird sentence, sorry!)
Also, if you click on 'new messages' then you can see if someone has posted something recently on back pages that you may have not checked. Once again, the messages you've read will be a different colour than the one's you haven't.
I like the system, personally!!
Although, yes, the time stamps aren't correlating...