squashfs errors when shutting down live session

When shutting down today's Live CD image (20100419), I get a number of squashfs errors, making it difficult to notice the 'remove CD' prompt:

end_request: I/O error, dev sr0, sector 446724
Buffer I/O error on device sr0, logical block 111681
Buffer I/O error on device sr0, logical block 111682
SQUASHFS error: squashfs_read_data failed to read block 0xd75e056
SQUASHFS error: Unable to read fragment cache entry [d75e056]
SQUASHFS error: Unable to read page, block d75e056, size 1bed7
SQUASHFS error: Unable to read fragment cache entry [d75e056]
SQUASHFS error: Unable to read page, block d75e056, size 1bed7
SQUASHFS error: Unable to read fragment cache entry [d75e056]
SQUASHFS error: Unable to read page, block d75e056, size 1bed7
error: unexpectedly disconnected from boot status daemon
init: plymouth post-start process (3862) terminated with status 2
init: plymouth main process (3861) killed by BUS signal
Please remove the disc and close the tray (if any) then press ENTER:
init: plymouth-splash main process (4085) terminated with status 1

This is on VirtualBox.