On Fri, 22 Jan 2010, Dave wrote:
On second thought, though, can your DVD RAM drive definitely read
DVD+R media? ("cdrecord -prcap"?)
That was my first thought as well, but Panasonic says that at least the "UJ880AS" can read pretty much anything. (Assuming that the final S just means the slimline variant.)
But for what it's worth, "Invalid argument" is what mount_cd9660 says if you feed it a *blank* disc, so I wouldn't rule out readability in some way or another. (Are you sure you got the right one, and not the failed first attempt at burning? Any problems reading plus/minus/RW discs in the past?)
You could just try reading from /dev/cd0a with dd, if that doesn't work then that's a pretty good indication that something's more seriously wrong.
MAgnus