User Activity

Up until today, no problems. From today when I go to create a new listing I can't get past the Item Category page. I have turned off the computer, restarted it, but no difference.
Why can't I read, archive or delete any of the messages in my Messages file? This has been happening for some months. I can't even email or telephone Ebay about it as the system won't allow me - all it does is ask me to select a subject and then it g...