php 4.3.8 is a tad old ...

php 4.4.4 is the more preferred version ...

I cannot recall if there are or are not issues with that version of php ...

I would try reloading the files in:
/zc_install

Then try loading all of the files the directories except the:
/admin
/zc_install

Then try loading the:
/admin

This is just limiting the upload in thirds to see if this corrects the problem ...

Then close all of your browser sessions, clear your cache and cookies ...

See if it goes better ...