I received my SH-S182D last Thursday, and had similar problems with it.
Turned out the drive was running in UDMA 0.
I don't want to be a Clever Trevor, but uninstalling the channels(s) in device manager is not going to help you.
In Device Manager, you need to uninstall the controller (not the channel) that your ODD is connected to, AND reboot.
(The controller is one level up in the bus hierarchy.)
When you delete the channel, there is no actual re-detection taking place.
The installed controller will only repair the channel to what it was before. And in your case it made a mistake.
And it will keep making that same mistake because, well, it is in control.
You have to kick the controllers butt to do a proper job.
So sack it, and let it re-apply for the job.
Uninstalling will take about 15-25 seconds, so don't fret.
After the reboot and login, everything which was connected to the controller you uninstalled will be re-detected.
All drives, primary and secondary channels, and the controller itself.
Let the yellow balloon text popups on the right-hand side of your taskbar finish. (XP might want you to reboot again, don't ignore it.)
Then check the transfer mode in Device Manager.
http://forum.imgburn.com/index.php?showtopic=59&pid=967&st=0&#entry967 (Wait to let your browser position to the correct posting.)