I have this dvd R75 model since yesterday. I did many things (record, copy, playback etc.( but there are several things, which doesn't work at all. 1. "Erase disc" option is in shadow and I cant't erase a RW disc. 2. "Lining up recordings within a title" (assemble cut) doesn't work 3. "Divide title" doesn't work Please give me some ideas.