Notice: Trying to get property of non-object... (common.inc)

Hi all,

I have attempted to migrate my Drupal site across from my MAMP local folder to a live server, but I receive the "White Screen of Death" with the following errors:

Notice: Trying to get property of non-object in xxx\includes\common.inc on line 906

Notice: Trying to get property of non-object in xxx\includes\common.inc on line 1807

Notice: Trying to get property of non-object in xxx\includes\common.inc on line 1807

I know that there is no problem accessing the database, as I installed Drupal on the live server and used the Backup and Migrate module to copy the database across (as well as manually copying across my Files folder).

Any idea what might be causing this? I've heard that changing the error reporting line in php.ini (to error_reporting = E_ALL & ~E_NOTICE) might help, but the technician is away today and I don't have access to it. Plus, I'm not sure if that's actually the problem, as none of the Drupal pages are actually loading (whichever URL I type in, they all return this result).

I've also disabled clean URLs, as I know our server doesn't support them.

I'm using Drupal 6.19, and the server is running PHP v5.1.6.

Thanks!