What Is It?

Following are two pictures of a bird who's specific ID is being discussed- see Ted Floyd's post on the Frontiers of Identification mailing list for more info and to follow the discussion. Click on each photo for an enlargement. Here's what I know about the bird:

Unidentified warbler (family Sylviidae)
Photographed 24 May 2008
Near Nasiriya, southern Iraq
(Photographer's name withheld for security reasons.)