Can No Longer Burn To External Drive

Question

About two years ago my then six-year-old 800 mhz flat panel iMac's SuperDrive started acting erratic. Rather than replace the internal drive I purchased an external LaCie firewire drive. I was able to both read and write from this drive.
I am not positive, but I believe that I subsequently upgraded to OSX 10.4.11. And not too long ago I had no trouble burning a music CD from an iTunes playlist in the LaCie drive. In any case, the other day I tried to burn a simple data DVD of some photos to a DVD in the LaCie drive. I have been completely unable to burn a disc. I've tried burning from the finder, burning via Backup, and burning via Toast. All have failed.
I have wasted about a dozen discs so far. Often the burn will seem to complete, but fail verification. Sometimes when it fails verification it says it was because of a data transmission error, other times it says a sector failed.
Other times the burn will terminate early and the disc will ejec. The error messages are never consistent. Sometimes it will say "Buffer Underrun." But the LaCie drive protects against that, and I've gotten the Buffer Underrun message even when burning at only 1X. Can't go any slower than that.
Blank media inserted in the LaCie drive takes a long time to appear on desktop, and appears as a folder with a "burn" emblem on it, not as a disc. I've tried swapping Firewire cables but that hasn't made any difference.
The internal SuperDrive is completely dead by now. If I insert a disc into the internal drive there is no startup noise, no whirring, etc. Eventually the machine just spits out the disc.
I don't need to burn discs often, but this is driving me nuts. Any help would be greatly appreciated. I get the impression that Tiger has a real problem burning to external drives.

Answer 1

Daniel,
For several years I've been burning optical media of every kind on what is likely your drive. (Because they're sensitive to mechanical trauma, I bought a Firewire/USB Multi-drive encased in a small tank my cat can't move.
Your desktop icon struck me. I fiddled with 'System Preferences', but couldn't reproduce it. (My choice for blank media is 'Disk Utility.) Normally, only mounted devices appear on the desktop: this means a file system compatible with the Mac's was recognized (after a lot of handshaking) and attached to it. Hence you can drag an object from the drive to the Desktop.
The other thing that struck me was the variety of errors, rather than one. This tends to support BDAqua's suggestion of power problems. I'd check the cable and its plugs carefully. If yor Superdrive reported a variety of errors as well, I'd suggest a problem with your iMac.
There were many problems with the LaCie drive when 10.4.9 appeared (big changes to the kernel). Kludges & hacks ran amok, but all everything has worked after a few patches by Apple. That was years ago. My LaCie (Samsung w/Lightscribe) has never had another problem
Does either of your drive burn CDs? This I ask because of BDAqua's second statement. There's nothing simple about DVD. An engineer, writing about how it worked, ended with 'it's a miracle it works at all'.
When a optical drive dies a natural death (all is ephemeral), the DVD lasers get knocked out of alignment or burn out first. CD continues working.
So, you know the routine: be sure your blank media are blank (or, try a DVD-RW to be safe), change buses if you can or cables if you can't, then try a friend's burner. You can visit LaCie and install a new driver. (Though, like Adobe, it has an installer installer.) I'm not sure whether you need to be in warranty to place a 'trouble ticket' with LaCie; but that's a possibility. The desktop icons would suggest an inconsistency at Apple (which is next to heresy) or a problem with your iMac. Perhaps other have seen this. In any case, your symptoms are not the typical ones expected from a naturally dying drive.