Problem uploading images

Hi

I keep getting an error trying to upload some images but not others in WP. WP says the images exceed the upload limit (1MB). I checked with my hosting service and the php.ini is set to 10MB max file upload. The files I’m trying to upload are iPad Retina sized Jpeg, all exported from Lightroom with a maximum size of 2048 pixels on an edge. The odd thing is that some images will upload fine but others won’t. I’ve tried resaving with more compression to get the problem files under 1MB but that doesn’t work. Help! I’m running out of options.

BTW I’m using a 3rd part theme, have networking enabled and 2 sites active on WP.