Hello,
I'm currently a loyal Debian user but as a former Mandrake and Mandriva user I wanted to see how is it today, so I've been recently testing Mageia, because it always seemed to me the easiest GNU/Linux for newbies, especially because of its powerful yet simple configuration tools.
So I downloaded the DualArch DVD and installed it into a VMware Player virtual machine, and besides some small annoyances, I've found one strange problem which I think it can be very difficult to solve by newbies as it avoids starting session at all, so I thought that writing this post could be helpful.
The symptoms: after entering a correct password at the login screen, the system comes back automatically to it, with no error message at all. You know that the password is correct because if you deliberately introduce an incorrect one, you receive an error message which is not shown if you enter the correct one. Besides, you can start the session with the root user (which is not recommended to use in a graphical environment). This problem happens only after changing some screen configuration (the resolution in my case) in a previous session (that is, you have started at least one session previously).
The investigation: after hacking a bit, even reconfiguring the screen from the command line through "drakxconf", I saw that the problem was that the file ".XAuthority" got owned by root instead of the regular user, so it was a permission problem which in fact appeared somehow in the file ".xsession-errors" (I got confused because at the same time I was getting some errors because of some "gtk-canberra" libraries not loading, but I solved it and it was unrelated).
The solution: When this problem appears, from the login screen start a command line session (just press [Ctrl]+[Alt]+[F2] to open the second console terminal), initiate a root session and do «chown yourusername:yourusername /home/yourusername/.XAuthority». Then you can close the text session, get back to graphical login screen pressing [Alt]+[F1], and start your regular user session.
The system: The problem occurs at least in a fresh 64 bits installation from DualArch DVD, with XFCE. I've reproduced the problem (and the solution) at least twice.
Greetings.