I downloaded Sabayon_Linux_DAILY_amd64_K.iso and made sure the md5sum was correct before burning it to a rewritable dvd disc using K3b
The burn process was successful according to K3b, I didn't check the md5sum and placed the dvd disc in my backup desktop and yes I ended up with the following error
isolinux: Disk Error 10, AX = 4200, drive FE
So I placed the dvd in my HP CQ61 Notebook and it did not work
So I grabbed a blank (LG) dvd disc and burnt another copy, allowing it to burn at the fastest speed, when it was finished, I placed the disc in my backup desktop and rebooted, the live dvd booted with no problems so I installed Sabayon_Linux_DAILY_amd64_K on to the the hard disk and it works OK
Now while Sabayon was being installed, I place the rewritable disc in my main desktop computer and attempted to create an image of that disc so that I could check the md5sum, the copy was unsuccessfully
Here is the K3b debugging output
DVDRW SATA 20X20X12X 9A31 (/dev/sr0, CD-R, CD-RW, CD-ROM, DVD-ROM, DVD-R, DVD-RW, DVD-R DL, DVD+R, DVD+RW, DVD+R DL) [DVD-ROM, DVD-R Sequential, DVD-R Dual Layer Sequential, DVD-R Dual Layer Jump, DVD-RAM, DVD-RW Restricted Overwrite, DVD-RW Sequential, DVD+RW, DVD+R, DVD+R Dual Layer, CD-ROM, CD-R, CD-RW] [TAO, Restricted Overwrite, Layer Jump] [%7]
reading sectors 0 to 1084714 with sector size 2048. Length: 1084715 sectors, 2221496320 bytes.
using buffer size of 64 blocks.
Problem while reading. Retrying from sector 2752.
Problem while reading. Retrying from sector 2816.
Problem while reading. Retrying from sector 2880.
Problem while reading. Retrying from sector 2944.
Read a total of 2944 sectors (6029312 bytes)
K3b Version: 1.70.0
KDE Version: 4.4.2 (KDE 4.4.2)
QT Version: 4.6.2
As you can see there was quite a few errors reading the disc so I couldn't create an image to check the md5sum
So to put it plain English the problem is the DVD Disc is faulty
The best way to make sure you have a successful burn is to pay a few dollars more and purchase decent disc(s) I mainly use LG or HP and when my supplier is out of stock I get Kodak, to many faulty disc(s) when using the cheap ones