I think basing on my experience it had to do with PERMISSIONS and SERVER issues, while working on this project with my client, it was hosted in a different server, when we did the MIGRATION to the new server, I did a CLEAN UP on all the permissions and did an increase on my PHP limits, everything went fine.
This is for me...so as far as my issue on this TOPIC - SOLVED it by
1.) Adjusting the Permission Limits
2.) Doing a CLEAN UP with the Clean Up file found in this site. (it changes and resets necessary permissions)
Hope this helps others. I know how frustrating it can get, been doing this website conversion for 2 months now and I almost to the end of it (or at least I hope)