I am having same issue, but I found a way around it.I go to my profile then click to write myself a new meeage and you can access all of your messages that way...silly, but its the only way I got it to work :)
The link in the tab does not work properly. I've reported this but I guess the webmaster has been unable to fix it.
To check your messages: Just go to .
same for me for a couple of weeks now.