PROBLEM Can't modify, update pages on new installation (all 755)

[shawn_a]

I would say permissions, but it is odd that you are redirected to root.
Which almost makes me think it is either A. bad rewrite in htaccess, B. incomplete upgrade, C. host is blocking and redirecting to a 404 that does not exist. ( this would be a mod_sec xss filter or something )

Either way check your error logs.. enable gsdebug etc. as per the sticky in general questions and issue
http://get-simple.info/forums/forumdisplay.php?fid=16