If neither writing at a slower speed nor changing your CD media works then i suggest you take your drive back and get a new one if it still has a warrantee
I had the same problem with my drive, it kept burning CD’s and would just stop the burn process with Write Medium Errors. HP advised me as did others here to try different CD’s, some worked and others did not till i found that 24X Verbatim’s were the most stable for my drive, but when the Verbatim’s started giving me endless problems after a while i thought it was necessary to take my drive back to HP and ask them what the hell was going on.
Well they just gladly swopped out the drive for me and with this new drive i tested all those other media which previously failed and they all worked
Im actually impressed with this drive of mine coz i never really checked the label on the drive but the one i received back from HP says it’s a LTR16102b. Which means it probably has a LITEON chipset, now i know why iwas able to backup all revisions of SD2. I havent tried SD2.60 yet.
But yes, try and get the drive swopped if the problem still persits.