Naturally the burn button is ghosted.
It's worked before... I barely sledgehammer this machine anymore...
A look at the console shows it chucking back:
** Message: Using UDEV
libburn-FATAL : Failed to transfer command to drive
libburn-( Most recent system error: 5 'Input/output error' )
libburn-FATAL : Lost connection to drive
libburn-FATAL : Failed to transfer command to drive
libburn-( Most recent system error: 5 'Input/output error' )
libburn-FATAL : Lost connection to drive
libburn-FATAL : Failed to transfer command to drive
libburn-( Most recent system error: 5 'Input/output error' )
libburn-FATAL : Lost connection to drive
libburn-FATAL : Failed to transfer command to drive
libburn-( Most recent system error: 5 'Input/output error' )
libburn-FATAL : Lost connection to drive
** (xfburn:2889): WARNING **: Unable to grab the drive at path '/dev/sr1' (ret=-1).
** (xfburn:2889): WARNING **: Couldn't grab drive in order to update speed list.
** (xfburn:2889): WARNING **: A pipeline element could not be created


Somehow the drive's supposed to be busy. It's not listed in lsof -K (not as /dev/s anything) though the kernel has been whining amain about the Fedora 4 disk (ready for rewriting, maybe) in the vein of
[611471.464059] blk_update_request: I/O error, dev fd0, sector 0
[611471.464069] floppy: error -5 while reading block 0
[611476.168396] sr 4:0:1:0: [sr1] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[611476.168406] sr 4:0:1:0: [sr1] tag#0 Sense Key : Medium Error [current]
[611476.168413] sr 4:0:1:0: [sr1] tag#0 Add. Sense: L-EC uncorrectable error
[611476.168420] sr 4:0:1:0: [sr1] tag#0 CDB: Read(10) 28 00 00 05 5f 0a 00 00 02 00
[611476.168425] blk_update_request: I/O error, dev sr1, sector 1408040
[611478.552312] sr 4:0:1:0: [sr1] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[611478.552323] sr 4:0:1:0: [sr1] tag#0 Sense Key : Medium Error [current]
[611478.552331] sr 4:0:1:0: [sr1] tag#0 Add. Sense: L-EC uncorrectable error
[611478.552339] sr 4:0:1:0: [sr1] tag#0 CDB: Read(10) 28 00 00 05 5f 0b 00 00 01 00
[611478.552346] blk_update_request: I/O error, dev sr1, sector 1408044
[611478.552353] Buffer I/O error on dev sr1, logical block 352011, async page read

That thing is on fstab as user mountable: /dev/sr1 /media/sr1 auto noauto,exec,users,ro 0 0

Is it merely time for a SCSI reset (SG something) or is it time to reseat cables and perhaps pick another SATA port?
Maybe the kernel hated that disk (and/or whatever's polling drives?)

Naturally the burn button is ghosted.
It's worked before... I barely sledgehammer this machine anymore..

So it was a daily burner earlier?

That thing is on fstab as user mountable: /dev/sr1 /media/sr1 auto noauto,exec,users,ro 0 0

Is it merely time for a SCSI reset (SG something) or is it time to reseat cables and perhaps pick another SATA port?
Maybe the kernel hated that disk (and/or whatever's polling drives?

It worked before. fstab has not changed unless you changed it. The kernel does not go schitzo (hate) that I know of.

See if your preferences are somewhat close to my working xfburn I guess. Sounds like something physically broke to me though.

libburn-FATAL : Lost connection to drive

Check that it isn't a 'closed session' disk.