** Whenever I log into the admin section, it seems to let me in. But if I try to do anything, the login page shows up again. **
That could happen if your browser wasn't accepting cookies, the script couldn't write to the session directory or some people have reported being over their web space quote would prevent the sessions files from being written to.
** All files have the 755 permission **
Only script files and their directory should be 755, the data files and their directories should be 666 (or 766 depending on the server).
JFYI
Dan O.
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