
You should have asked before dumping the computer copies. That this is the way the system works isn't a design error so much as you deleting the photos from your computer before fully understanding the system is a user one. If you removed a photo from the computer the system assumes that you did this because you don't want the photo and it will remove it from everything. Because the act of syncing is to keep your collections identical with the computer as the master of the action in the case of photos. Now if you are saying that you imported them, loaded them in iPhoto or a folder of photos and synced them back to the iPad in the regular photo library and then removed them from the computer, yes the next sync will delete them. So if these old photos are still in your camera roll they are fine. Doing a sync doesn't erase them or import them. The photos in your camera roll are not affected by syncing.
