Old Problem/New Problem: Lightroom can't find file, then finds, but won't edit it.

Question

(Lightroom 2; Macintosh G5; OS X (10.4.11))
First, the old problem which, though unresolved, is here mostly for background:
A little over a month ago, I posted a question (at http://forums.adobe.com/thread/480423?tstart=0 ).
The short version of that problem is that certain previously accessible images were not able to be opened in Lighroom. The preview image appeared in the main window accompanied by this message across the top of it:
"The file named "[name of image/file]" is offline or missing."
When I right clicked on the image and selected "Show in finder" I got this message:
"The photo '[name of file]' could not be used because the original file could not be found. Would you like to locate it?"
Below which was shown the original path to the file. In the middle of that path, one or more folders appeared with colons in their names in place of the slashes originally part of the names (some folders have dates in their names). Following the path via the Finder, the file was exactly where it was supposed to be, although, of course, slashes appeared instead of the colons that were in the Lightroom summary of the original path, but Lightroom couldn't find them.
I was convinced that Lightroom was renaming the folders (but only in its interface; the original folders had correct names in the finder -- which is the only way they could have been named, since colons are illegal characters and won't be accepted as part of a file name). But I see now that there is some weird thing going on in the Finder itself. Even though I see the correct name on a folder when I search for it, or navigate through the hierarchy, if I click on the file at the end of that hierarchy (the file that Lightroom said it couldn't find) and ask for file info (via Command - I, or other method), the path to that file shows colons where slashes should be, but only in the names of the folders that were so named in Lightroom. All other folders with slashes in their names are listed correctly. So it's a Finder problem. Though this is still a mystery, I have been able to work around the problem. But how is this happening? (Note that I will be reformulating the question and posting it on the Apple discussion groups soon; I don't expect this forum to deal with Apple system issues. Just thought that others here may have had the same problem.)
Now, the new problem, possibly related to the old one:
In the same collection where I noted the previous problem, I selected an image that I wanted to print. The preview came up with this message:
"The file could not be found."
But when I right click on the image and select "Show in finder" it opens the correct Finder window with the file in question highlighted. The file, a TIFF, opens normally in Preview or Photoshop.
So why does Lightroom think it's not there? (even though it can show me exactly where it is)
I have edited this photo in Lightroom before. I have printed it from Lightroom before (as shown in the Lightroom history). But today it can't be edited, won't print and "could not be found"!!!
I know I can print from Photoshop, or re-import this photo into Lightroom (along with any others that Lightroom "can't find"), though both would require time and re-editing the original. I would rather understand (if that's possible) why this is happening in the first place, so hopefully I can avoid such wackiness in the future.
I realize that may have to burn some sage and hire a Shaman, but any ideas that won't smoke up the house or scare the cats would be most welcome.
Thanks for reading.
Leonard B.

Answer 1

If you have an old goat around that's not doing so well, consider the sacrifice.
The one thing that occurs to me besides the Gremlin, is the use of colons or slashes or some other character that the OS or LR doesn't like in some file name or other.  I think you'd have to change same in Finder, then show LR where the images are.