My suggestions: verify the md5sum's / sha1sum's of the burned CD/DVD's. (Since you already have the apparently correct iso downloaded to disk). How? like this: dd if=/dev/dvd bs=xxx count=yyy | md5sum (/dev/dvd is your dvd/cd whatever device, might be /dev/cdrecorder, /dev/cdrw, /dev/dvd, /dev/dvdrw, /dev/hda, /dev/hdb, /dev/hdc, /dev/hdd, etc... you should know ;-) ) Where xxx and yyy satisfy the constraint xxx * yyy = size of iso image in bytes. Preferably you want xxx as large as possible. Since iso's are written in 2KB sectors, you can always use 2048 for xxx, but bigger is better (better = faster). If I've lost you, then just do: ISOSIZE=... dd if=/dev/dvd bs=2048 count=$[$ISOSIZE/2048] | md5sum Where you would replace the three dots with the size of the iso image that should have been burned to that cd/dvd. This will allow you to do a mediacheck by hand. I'd venture to guess they'll fail... if so, then burn on good media at minimum speed (ie. like 1x, or 2x, or something) - although I know you've tried this... I'll just add my 2c - I burnt the DVDs with no problem at 4x, and the above mentioned verification passes. Cheers, Maciej.