If I may add, i just checked the exif funtionallity a couple of weeks ago...
It works, but it depends much on the php version.
I tested 10 images, from 10 different different cameras
1 Ricoh model did not work at all, and 2 Olympus models show different exif information if you are under PHP 5.1 and 5.3 (i did not test php 5.2)
I think I read somewhere that flickr does not use the basic php modules to read exif (and other file information) they have proprietary executables that do the work on cascaded servers. So it is Normal that flickr does not give the same results as the standard php modules do. And I also read that php has problems with the header of jpg coming from some Nokia symbian phones. As It is a known issue, possible that flickr adapted their software, and that php did not.