Howdy,

This will probably be a pretty incomplete bug report because I am short on time at the moment, but please ask for whatever else you might need and I will 
try to follow it up.

The story goes like this - I have this MythTV box running Ubuntu 8.04 with their 2.6.24 kernel and DVD playing is pretty flawless. At some point I tried 
custom compiled vanilla 2.6.25 and that didn't work to well. From memory, something in the libata-scsi-sr-hardware chain would easily get confused, there 
would be numerous error messages logged and whatever.

So couple of days ago I went and tried with 2.6.26. That seems even worse in this respect. First DVD I put in and absolutely nothing happened, media 
wasn't recognised at all. Eject button wouldn't work and since it was a "projection" time I had to quickly reboot back to Ubuntu's 2.6.24 which had no 
problems with this DVD. Later I picked up the logs and some pieces of relevant information and decided to report it.

Below you will find one line from lspci, excerpt from kernel log and attached is complete 2.6.26 configuration. I hope I am not missing something there? 
Hopefully someone will be able to make some sense of it.

Regards,

Tvrtko

00:14.1 IDE interface: ATI Technologies Inc IXP SB400 IDE Controller

Jul 25 19:06:17 media kernel: [    3.063550] scsi2 : pata_atiixp
Jul 25 19:06:17 media kernel: [    3.063706] scsi3 : pata_atiixp
Jul 25 19:06:17 media kernel: [    3.064592] ata3: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0xf900 irq 14
Jul 25 19:06:17 media kernel: [    3.064595] ata4: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xf908 irq 15
Jul 25 19:06:17 media kernel: [    3.234566] ata3.00: ATAPI: TSSTcorpCD/DVDW SH-S182D, SB04, max UDMA/33
Jul 25 19:06:17 media kernel: [    3.272509] ata3.00: configured for UDMA/33
Jul 25 19:06:17 media kernel: [    3.424047] scsi 2:0:0:0: CD-ROM            TSSTcorp CD/DVDW SH-S182D SB04 PQ: 0 ANSI: 5
Jul 25 19:06:17 media kernel: [    3.424047] ACPI: PCI Interrupt 0000:02:01.0[A] -> GSI 20 (level, low) -> IRQ 20
Jul 25 19:06:17 media kernel: [    3.481008] firewire_ohci: Added fw-ohci device 0000:02:01.0, OHCI version 1.0
Jul 25 19:06:17 media kernel: [    3.483368] ACPI: PCI Interrupt 0000:02:03.0[A] -> GSI 21 (level, low) -> IRQ 21
Jul 25 19:06:17 media kernel: [    3.484574] eth0: RealTek RTL8139 at 0xde00, 00:17:31:9d:c0:82, IRQ 21
Jul 25 19:06:17 media kernel: [    3.491374] Driver 'sr' needs updating - please use bus_type methods
Jul 25 19:06:17 media kernel: [    3.497626] Driver 'sd' needs updating - please use bus_type methods
Jul 25 19:06:17 media kernel: [    3.497717] sd 0:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
Jul 25 19:06:17 media kernel: [    3.497729] sd 0:0:0:0: [sda] Write Protect is off
Jul 25 19:06:17 media kernel: [    3.497751] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
Jul 25 19:06:17 media kernel: [    3.497799] sd 0:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
Jul 25 19:06:17 media kernel: [    3.497809] sd 0:0:0:0: [sda] Write Protect is off
Jul 25 19:06:17 media kernel: [    3.497830] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
Jul 25 19:06:17 media kernel: [    3.497833]  sda:sr0: scsi3-mmc drive: 48x/48x writer dvd-ram cd/rw xa/form2 cdda tray
Jul 25 19:06:17 media kernel: [    3.498561] Uniform CD-ROM driver Revision: 3.20
Jul 25 19:06:17 media kernel: [    3.501805] sd 0:0:0:0: Attached scsi generic sg0 type 0
Jul 25 19:06:17 media kernel: [    3.501827] sr 2:0:0:0: Attached scsi generic sg1 type 5
[snip]
Jul 29 21:10:03 media kernel: [353032.319013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.319013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.319013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.319013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320016] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320025] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320034] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320043] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320053] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320062] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320071] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320077] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320083] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320090] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320096] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.320102] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.430059] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.430090] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer
Jul 29 21:10:03 media kernel: [353032.477013] sr 2:0:0:0: [sr0] unaligned transfer