Site functionality problem

Hi
My site is having an issue with Fatal Error. http://www.saia.saoma.co.za/
We try to do all possible combination to solve this issue.
1) We try to disable modules which is having an issue. No result
2) Delete module folder from FTP. No result
3) Change DB name and use backup DB. No Result
4) Use Backup DB and use this DB with fresh Drupal Installation. No Result.
5) Fresh Drupal installation and use older DB installed with all modules. No Result.

All this combination we already tried but still we get this error. This is our live site and we need this site to be up very soon.

Please help as soon as possible.

Thanks
Riddhi Parikh