Upgrade to 2.3 -- file permissions error

Hi. I receive "file permissions error" during upgrade to v2.3 However, the data directory is 0777. Site is www.ceiba.org/gallery. Apache server version 2.2.11 (Unix). PHP version 4.4.8. MySQL version 4.1.22-standard-log. Browser Firefox 3.0.5.

I looked at FAQ and the folder permissions are 0777, and version.dat exists; FAQ says post to forum.

One potential problem. I have two g2data folders, I think because of security recommendations I read during initial install, but perhaps followed poorly. Currently, albums are stored in ceibaorg/g2data/, but there also exists ceibaorg/public_html/gallery/g2data. The upgrade wizard error message indicates the LATTER directory has permission error. Both, however, are set to 0777.

Suggestions? Please note that I am very new to php, etc., and so I would very much appreciate replies in "english", when possible, rather than "server-administrator-ese"!