XP not seeing DVD drive

Hi,

My DVD drive was working fine. I put in a CD-RW and recorded to it. From that point on every time I tried to access the D: drive the files that I copied to the disc came up (instead of the files actually on the new disc inserted) and said they're ready to be copied. I told it to delete those temp files. Now, every time I insert a disc nothing shows up in My Computer or Windows Explorer. It's as if I inserted a blank disc.

What's going on?

WinXP SP3