DVD Drive doesn't detect media

[Oifish]

My roommate recently bought a Dell Inspiron 513s, and now the DVD drive doesn't find any type of media (CD, DVD, CD-R, DVD+-R). It is detected in the BIOS and the device manager in Vista finds it as well. The type of drive is an Optiarc DVD+-RW AD-7200 SCSI. Thanks for any help.