DVD-Rs burned in K3b aren't viewable in Ubuntu

I use k3b to create Data DVD-Rs, generally using the default options but with UDF enabled (I occasionally need to write large files).

The finished DVDs are not mountable or viewable in any version of Ubuntu I've tried so far:

 - Hoary Hedgehog
 - Breezy Badger
 - Dapper Drake Flight 4

I have tried all of those on my home PC which has a Pioneer DVR-106D DVD+/-RW drive and have tried Hoary and Breezy on my Laptop which has a CD-RW/DVD-ROM drive. None of them works, giving the errors listed below.

Strangely, though, I've tested the same DVD-Rs on several other Operating Systems on the same hardware and these all work:

* Kubuntu (somewhat strangely)
* Debian
* Fedora
* Knoppix

Additionally, I've tried the following Operating Systems on different hardware, all of which work:

* CentOS
* Windows XP Professional
* Microsoft Xbox (using the in-built DVD-ROM drive)

Here are the messages which appear in dmesg on Kubuntu (which works):

----------
[4329265.408000] cdrom: This disc doesn't have any tracks I recognize!
[4329265.885000] scsi: unknown opcode 0x01
[4330904.811000] ISO 9660 Extensions: Microsoft Joliet Level 3
[4330905.090000] ISO 9660 Extensions: RRIP_1991A
[4331468.614000] ISO 9660 Extensions: Microsoft Joliet Level 3
[4331468.783000] ISO 9660 Extensions: RRIP_1991A
[4341176.722000] cdrom: This disc doesn't have any tracks I recognize!
[4351003.498000] ISO 9660 Extensions: Microsoft Joliet Level 3
[4351003.549000] ISO 9660 Extensions: RRIP_1991A
----------

... and here are the error messages which appear in dmesg on Ubuntu (which doesn't work):

----------
[4294852.709000] ATAPI device hdc:
[4294852.709000] Error: Not ready -- (Sense key=0x02)
[4294852.709000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294852.709000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294852.709000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294854.759000] ATAPI device hdc:
[4294854.759000] Error: Not ready -- (Sense key=0x02)
[4294854.759000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294854.759000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294854.759000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294856.809000] ATAPI device hdc:
[4294856.809000] Error: Not ready -- (Sense key=0x02)
[4294856.809000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294856.809000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294856.809000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294858.859000] ATAPI device hdc:
[4294858.859000] Error: Not ready -- (Sense key=0x02)
[4294858.859000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294858.859000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294858.859000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294860.915000] ATAPI device hdc:
[4294860.915000] Error: Not ready -- (Sense key=0x02)
[4294860.915000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294860.915000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294860.915000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294862.965000] ATAPI device hdc:
[4294862.965000] Error: Not ready -- (Sense key=0x02)
[4294862.965000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294862.965000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294862.965000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294865.015000] ATAPI device hdc:
[4294865.015000] Error: Not ready -- (Sense key=0x02)
[4294865.015000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294865.015000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294865.015000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294867.065000] ATAPI device hdc:
[4294867.065000] Error: Not ready -- (Sense key=0x02)
[4294867.065000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294867.065000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294867.065000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294869.115000] ATAPI device hdc:
[4294869.115000] Error: Not ready -- (Sense key=0x02)
[4294869.115000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294869.115000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294869.115000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294871.165000] ATAPI device hdc:
[4294871.165000] Error: Not ready -- (Sense key=0x02)
[4294871.165000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294871.165000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294871.165000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294873.215000] ATAPI device hdc:
[4294873.215000] Error: Not ready -- (Sense key=0x02)
[4294873.215000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294873.215000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294873.215000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294875.265000] ATAPI device hdc:
[4294875.265000] Error: Not ready -- (Sense key=0x02)
[4294875.265000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294875.265000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294875.265000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294877.315000] ATAPI device hdc:
[4294877.315000] Error: Not ready -- (Sense key=0x02)
[4294877.315000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294877.315000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294877.315000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
[4294878.316000] ATAPI device hdc:
[4294878.316000] Error: Not ready -- (Sense key=0x02)
[4294878.316000] Incompatible medium installed -- (asc=0x30, ascq=0x00)
[4294878.316000] The failed "Read Cd/Dvd Capacity" packet command was:
[4294878.316000] "25 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
----------