I am just trying the message forum. I notice that I have just posted a response to start it - and the date shown is my registration date or at least some other date that is not the date I posted it (today). I searched preferences and edit site pages and could not find a place to set the date/time. As a guest on another site, it seems to work fine - what do I need to change?

When a post is made in the Message Forum for the first time, an initial message is posted and it is dated to the registration of the site. I don't know why that is done. If you don't want it, you can delete it and post a new response, and it should be dated at the time you post it.