Lightroom Help

I have LR3, and I have all of my photos linked to my external hard drive.
My photos from 2011 show up as missing files. I only get about 400 of them.
I can find the files on my drive, through Time Machine.

I have tried Synchronizing, it shows that there are no photos to synch.
I have tried re-installing the entire 2011 file from Time Machine- still doesn't show the photos.

Any ideas? After the re-install, the 2011 file on LR3 shows a lot more photos, but when I pull it up, all the same files are still showing as missing.

Not sure if it's the same problem, but when I've moved the original files from one folder to another, LR obviously cannot find the files. Here's how to fix it in LR4:

The images with missing files will show a ? symbol in the corner of the thumbnails.
Click on the ? symbol (can't remember if left- or right-click).
It'll bring up a dialog box asking you to point to the correct file -- navigate to where the file is and select it.
In that dialog box there is also a check-box for locating nearby missing files -- check that for LR to find the other missing files if they're in the same folder.

Again, that's how it works in LR4. Not sure if it's the same in LR3, or if you even have the same problem.

Thanks Fuzz. That got me in the right direction. Turns out you can right click the entire file and locate it. Once I moved them all out of a subfile, they all populated. Thank god for Time Machine.