Unable to add image

Maybe related to:
http://omeka.org/forums/topic/omeka-20-issues#post-20702

but when trying to add an image, I get the following message:
Omeka has encountered an error

To learn how to see more detailed information about this error, see the Omeka Codex page on retrieving error messages.

When i try to edit the .htaccess file in the root, I do not see an entry for:
php_value display_errors

The method for enabling errors is different in Omeka 2.0.

The Codex page Retrieving Error Messages 2.0 has the new instructions (you uncomment a SetEnv line).