I just upgraded to Drupal 7.8 and began encountering this (fatal) error:
EntityMalformedException: Missing bundle property on entity of type file. in entity_extract_ids() (line 7389 of //includes/common.inc).
Disabling the File Entity module caused it to go away. (Uninstalling and re-enabling caused the error to come back.)
(I just realized the File Entity module is it's own project, though it appears in the Media group under Modules. I am using the latest -dev version of file_entity.)