The "no additional sense information" message is SCSI jargon for an unspecified error returned by the hardware, hence the all-zero code (http://www-uxsup.csx.cam.ac.uk/redhat/howto/SCSI-Programming-HOWTO).
You've got 48000+ POFs, or outer Reed-Solomon code failures to correct data errors, by the time scanning came to a halt around 4.25 GB. This disc is essentially unreadable past the 4 GB mark (the last 4 mm or so near the outer edge of the purple-colored recording surface).
I would check the lower side of the disc for damage around the outer edge: dots, marks, scratches, discoloration, dye defects, plastic layers coming unglued at the edge, anything else different from the bulk of the surface that recorded well.
I've burned a 25-pack of these (Verbatim movie-reel 4x DVD-Rs) on a DW1620 with B7P9 firmware, and the ones I scanned were all good with PIFs never exceeding 6 to 8 all the way to 4.37 GB. Don't give up, try another disc from the middle of the pack.