Hi, Our iBook G4 won't recognize DVDs. It reads CDs fine, and I just upgraded the OS to Tiger and it read that DVD as well. However, when inserting a regular DVD (movie, etc., original copy, not burned) it says "this disc contains no volumes recognized by OS". I reinstalled the original OS and software, upgraded to Tiger and have reset the computer and checked the system preferences to make sure it wasn't set to ignore DVDs. The player worked in the past, not sure what is going on. Thanks in advance for any advice/help.