hey mark, this is a long standing (4 year old) bug: 4964815 Unable to burn CD's inside a non-global zone i just did some quick testing and i think the crux of the problem is that to burn cds, both cdrw and cdrecord need to issue uscsi commands, which currently requires the sys_devices
You may find that 6712352 is a related bug (on sparc). (not having to do with non-global zones per se) Once you burn a CD/DVD you can't mount it properly. workaround: svcadm disable -t volfs then mount dvd manually with mount command. Took me forever to find the cause of the problem.
does the zone have an exclusive ip stack or a shared stack? it might be interesting to compare packet snoop data (with timestamps) taken for the global zone for a transfer from a remote host to the zone vs a transfer of the same file from the global zone the the zone. you would probably also