I've got an Aperture library I busted up into smaller libraries—one for each year—and when I convert one of those smaller libraries to Lightroom with Avalanche 1.3.4, out of 11,000 images, about 7,500 of them lose all their EXIF and IPTC data. I opened the Aperture library back up in Aperture, and all the data is there, so Avalanche is dropping it for some reason.