OK, I did a complete re download and re-install of the system. Right from the first log in in the admin GUI, using the password given on first execution of the rocket server to create the parameters file, I get the double logo as soon as I enter the admin area. See what it looks like here: http://i.imgur.com/7LZGP.png
Note: this is web2py out of the box. No change at all. I know the system recognizes the password because if I enter a wrong one it gives back a message to that effect, and if I give the right one it doesn't it just presents the login screen again although I appear logged in. Has anyone got any ideas?

