Missing Desktop/Screensaver in System Preferences

Could use help from you all:

Using 10.5.1, no problem up until now (new 2.8 iMac). Working all day with Adobe Lightroom 1.3.1, again, no prior problems.

The computer froze, which I noted when the screensaver when I left to go eat dinner stayed static without fading out to a new picture. After force quitting and restarting, I went to the System Prefs and when I went to the Desktop/Screensaver section, I got a blank window. I confirmed all the other System Prefs icons work fine. It's as if the Desktop/Screensaver settings are erased/gone/whatever.

Anyone with any suggestions, I'm ALL ears.

Thanks in advance.

I think I fixed it, after I figured out what I did....

(For those of you who know about jpegs, RAW files, and metadata,) I changed the metadata on a bunch of my jpegs in Lightroom, and corrupted them. When the Screensaver kicked in, it had corrupted jpegs to work with, and the whole thing crashed.

I deleted some plist files, TimeMachined my original jpegs back, and now life is good. I've spent the past few hours sweating a bit, though.

And something a little quirky: the screensaver, when it kicks in, now takes about 10 seconds (versus immediate) to show the first pic from the file. Nevertheless, this is still better than Windows!

Thanks for the help anyway, I appreciate the tip.