I think you have a driver problem, not a hardware problem.
I have the Pioneer BD-RW BDR-205.
The DVD/CD-ROM driver is called cdrom.sys
The folder is correct, but the file name is wrong.
I think you have a nasty file there.
Check the C:\Windows\system32\drivers folder for the cdrom.sys file.
If you have it, then delete the UBHelper.sys file and reboot.
You want the DVD device to show the cdrom.sys driver.
By the way, do you have anti virus software installed?
Way wrong answer....
Try the following MS KB article:http://support.microsoft.com/kb/314060
Try following the steps for Windows XP/Vista which may also work for Windows 7.
The UBHelper.sys is a driver for NTI software, such as NTI CD & DVD-Maker.
Do you have any such NTI software listed in your uninstaller?