Burner drive Error

Question

I have two burners in my mac pro. my top burner has started giving me errors... if I use iDVD it doesnt see the burner when I go to burn a dvd. DVD Studio pro works on it sometimes and burns fine. Toast gives me the error that it is a unstabe connection. I still you it to read from just fine. Everything has worked before so how can I fix this thing?

Answer 1

I also have identified a burner error caused by 10.5.7.
After upgrading, my DVD burner's cache size is repeatedly being scrambled after a couple successful burns, rendering the drive unable to successfully burn again until I reboot. This repeatedly happens when booted from my 10.5.7 partition, but never ever happens under 10.5.6 (or earlier).
see my post:
http://discussions.apple.com/thread.jspa?threadID=2013029&stqc=true
To further explain:
I have a MDD G4 (dual 867Mhz) with 1GB RAM and a Radeon 9800 Pro video card. I have four internal hard drives (1.25TB total) and two internal DL DVD burners (a Pioneer DVR-115 and a Toshiba Lightscribe SH-S202N). The Toshiba device is my primary burner, and I use Toast (either 9.0.5 or 10.0.2) to burn DVDs on a very regular basis. After uploading to 10.5.7, an annoying problem keeps re-occurring. After successfully burning 1-2 DVDs, Toast stops recognizing that the Toshiba DVD burner exists. And will not recognize the drive as a writable device until I shut down and reboot. Disk Utility 11.1 continues to see the drive, but I have not attempted to burn with it. Even though Toast (either version) refuses to recognize that device anymore, nevertheless CDs & DVDs inserted in it will still mount on the desktop and can be accessed normally. I can still burn discs with my Pioneer drive when this problem is in effect, but the failure rate increases to about 50% regardless of the media type. So it appears to be affecting my second burner, but in a more limited way.
When I boot off my 10.5.6 or 10.4.11 partitions, this problem never happens, and both bruners perform flawlessly. But it repeatedly happens when booted into 10.5.7 after I sucessfully burn 1 or 2 DVDs. Also, I notice that after the problem occurs, in System Profiler 10.5.7, it lists that the "Cache" (size) of my Toshiba burner as 65536K (whereas, before the problem is in effect the same drive reports a cache size of 2048K--the true size). All the other device info remains correct. So I suspect that there is some bug in 10.5.7 that causes the ATAPI driver to modify the reported cache size for the device, which freaks Toast out so much that it simply ignores that the drive exists anymore. Restarting the Mac doesn't reliably "reset" the drive back to normal, but shutting down--waiting for 10 seconds--and restarting always works in resetting the situation.
I originally updated to 10.5.7 using System Update, but then re-upgraded using the 10.5.7 Combo Updater, but that had no effect on the problem.
I have not encountered any other problems with 10.5.7, but I cannot use 10.5.7 unless this problem is solved by Apple.