The first thing one thinks of with these sorts of errors is that the 
machine is having a problem making sure that the buffer is never empty.  
I believe you said earlier that you don't have access to those 
messages?  Is there a way to turn them on, or provoke increased 
verbosity, or increased logging verbosity (or any damn thing that gets 
you more information)?  It's easy to speculate, but some nice, solid 
information is always better than any speculation.
   
growisofs does not provide much info regarding buffer/fifo fill % like
cdrecord does. Cdrecord has no problems keeping the buffer above 95%
full, so the system does not have some fundamental flaw... I do wish
growisofs could provide more info.
 
It might be interesting to try the version limited to 1gig writes, and 
see if the results still match what you observe (errors after about 500 MB).
   
I'll see how far the write gets with DVD-R media, then post again.
 
The common procedure is to have a bootable MS-DOS disk used to change 
firmware, since it can't ordinarily be done in protected mode.  With a 
bootable floppy (or a bootable CD, for that matter, using Syslinux in 
floppy emulation mode) you shouldn't have to physically move the drive.
   
That's what I had for motherboard and displaycard firmware, and it could 
be sent to disk with dd. I will investigate drvupdate.com more, but 
first thing I saw was nice screenshots of windows wizard-like 
application... if it is simply a windows-wizardlike-dd which is then 
followed by a reboot from disk, then maybe it will work in Wine. Or of 
course I can borrow another machine. Will investigate, thanks!