If there is no "sessions" subfolder in moodledata folder then your moodle is saving sessions to database and missing permissions of sessions folder is not causing your problem.
When you move files with FileZilla they may be moved as Ascii files and hashed files in moodledata can get corrupted. Filezilla has an option to force binary type transfer from
Transfer > Transfer Type > Binary
The default setting is Auto (ZileZilla should detect the correct type)
There have been various reasons for "blank pages" in the past and usually the reason can be pretty simple, some tiny setting in server environment or php, a .htaccess file in a wrong place, some security module (mod_security) etc.
When I visited your site and tried to login as a guest I see
Warning: require_once(/home/ci8156/public_html/moodle/lib/htmlpurifier/HTMLPurifier/AttrValidator.php) [function.require-once]: failed to open stream: No such file or directory in /home/ci8156/public_html/moodle/lib/htmlpurifier/HTMLPurifier.safe-includes.php on line 20
Fatal error: require_once() [function.require]: Failed opening required '/home/ci8156/public_html/moodle/lib/htmlpurifier/HTMLPurifier/AttrValidator.php' (include_path='/home/ci8156/public_html/moodle/lib/zend:/home/ci8156/public_html/moodle/lib/pear:.:/usr/lib/php:/usr/local/lib/php') in /home/ci8156/public_html/moodle/lib/htmlpurifier/HTMLPurifier.safe-includes.php on line 20
by Mauno Korpelainen.