Our SharePoint 2007 farm contains some files -- in multiple document libraries -- that mysteriously cannot be modified and saved. This is NOT a permissions issue -- even the farm administrator can't modify them. They are all MS Office files.Using the web UI, a user opens an MS Word 2007 file for editing (not for reading). Regardless, the Word UI says the file is read-only in the title bar, but not in the usual place (the bar across the window that offers you an "Edit Document" button is absent). You can make a change within Word, but when you try to Save, instead of saving, the user is prompted for for a file name. You select the original file and click save, and the error appears: "This file is read-only."At the same time, another Word document IN THE SAME FOLDER can be edited and saved without any problems, so it's not folder permissions.Here's the weirdest part. We have .txt files that can open and save fine in Notepad, but if you open the SAME txt files in Word, they appear read-only in the same way as above.The file paths and URLs are short, well under 250 characters. So this isn't a name-length problem.The client operating systems are Windows 2003 Server and Windows XP.The problem seems to happen when you access SharePoint via WebDAV, right-click and choose "New... Microsoft Office Word Document" and then open & edit the document. But this is not the only time it happens.This problem has just surfaced on a year-old farm. We have not upgraded anything recently. Any ideas? (I haven't rebooted the farm yet.)

It gets stranger when you try checking out the document. The checkout works fine, but when you click to open the document (in the web UI), you get an error dialog:"The Office XML file New Microsoft Word Document.docx cannot be opened because there are problems with the contents."Click OK and you get:"Word found unreadable content in "New Microsoft Word Document.docx". Do you want to recover the contents of this document? If you trust the source of this document, click Yes."Click Yes, and you get the first error dialog again. Click OK, and you're done: Word does not open the document.Note: There is NOTHING CORRUPT about this document. It is an empty file! And if you drag it to your desktop (say, through WebDAV), you can edit and save the copy just fine.

Another possible clue: this past weekend, some Microsoft security patches were installed on our PCs.http://www.microsoft.com/technet/security/bulletin/ms10-feb.mspx

I have a similar problem but using the SP 2010 beta. Did you ever find revaluation?

No. We burned and down and reinstalled Windows & Office on some of the affected client PCs, which seemed to help. But it keeps happening to more & more people in our office.