g_vfs_done()...errors

[barbara]

Hello,
while reading/writing dvd on 6-STABLE (can't remember on 7-STABLE right now), I'm getting the message buffer filled by errors.
This is my dvd-rw
$ sysctl dev.acd.0.%desc
dev.acd.0.%desc: PIONEER DVD-RW DVR-109/1.58
attached to
$ sysctl dev.atapci.1.%desc
dev.atapci.1.%desc: VIA 8237A UDMA133 controller

And the followings are some examples of the error:

g_vfs_done():cd0[READ(offset=3533693165190270976, length=2048)]error = 5
g_vfs_done():cd0[READ(offset=8751655366962446336, length=2048)]error = 5
g_vfs_done():cd0[READ(offset=8751655370713257984, length=2048)]error = 5

g_vfs_done():acd0[READ(offset=3533693165190270976, length=2048)]error = 5
g_vfs_done():acd0[READ(offset=8751655366962446336, length=2048)]error = 5
g_vfs_done():acd0[READ(offset=8751655370713257984, length=2048)]error = 5

Is it possible such a value for offset (DVD-SL)?
Does anyone know the reason of the error?
Should I be somehow worried?

Thanks