I'd suggest trying a different, major brand (some drives are a bit sensitive to DL). Also, if your drive firmware doesn't recognise the specific media code on the disk (other than bugs, the media lookup table is typically what drive firmware updates, er, update) it may be picking the wrong read strategy for the disc. One simple thing you can try (which may also fix your Toshiba player problem) would be to find the tickbox in your burning software that forces the booktype to "DVD-ROM".
This all assumes, of course, that you're burning a valid image, which it doesn't sound like you are.