Pages document "could not be read" bc. it "does not have a valid format"

Question

The document in question was properly saved and Pages was not open when my computer hung as it was shutting down. MS Word would not quit or force-quit and I had to hard restart the computer. When I later tried to open this Pages document, which I had been working on before Word froze, Page would not open it and responded with the error message: "This document "document_name.pages" could not be read. This document does not have a valid format." When I looked at the document in question I noticed that its file size was 0KB. I have no idea why this happened, but I suppose it has to do with my computer not shutting down properly and perhaps with Word freezing. If I repair my drive permission, re-index it, anything, will it help? Just a note on the status of this machine: spotlight stopped working earlier this morning and I was waiting to finish this document before repairing disk permissions and trying to fix that issue with Spotlight.
In the meantime I have tried various fixes. First I tried to change the file ending to .zip, unpack it and open it. Then the same, but this time I tried to view package contents. It doesn't show up in the contextual menu as even having a package to show the contents of. The file is effectively empty, but I don't know where the contents went! The funny thing is that the MS Word doc was recovered automatically. Is it possible that Pages doesn't have an auto-recovery mechanism?
I need this file urgently, or at least the text in it. It is the bibliography of an important paper due tomorrow at 5 pm.Any advice or suggestions would be greatly appreciated.
BTW, I have used a file-recovery program in the past. It is called "Stellar Phoenix" and it worked wonderfully to find a Word doc that I accidentally deleted. It can't find .pages document though. In order to do so, I would need to tell the program what the average file size is, as well as the header information as follows. "Header (in hexadecimal)" "At Offset (in decimal)". I have no idea what this means, but if I could insert it, perhaps it could find the lost data. Should I have it search for .pages, .zip, .xml? I'm at a loss, but I know that it doesn't recognize .pages. In the meantime, I sent a support email to them and will see what happens.
Thank you for your help.
David

Answer 1

I can't respond before.
When the system say that your file size is 0KB, it means that nothing was saved. Only a file descripto exists.
So, there is nothing to recover.
Given the time the system crashed, you may have :
(1) a simple descriptor with nothing written
(2) a folder with every or only some of the required files.
In this case, Phoenix is useless : it's unable to revive a folder.
(3) a flatfile (a compressed version of the folder named above). It's only this kind of file which Phoenix may revive.
With a bit of luck, Phoenix would be able to revive the index.xml file which was in the original folder created in the temporary folder.
This file starts with :
<?xml version="1.0"?><sl:document xmlns:sfa="http://developer.apple.com/namespaces/sfa"
or
<?xml version="1.0"?>
<sl:document xmlns:sfa="http://developer.apple.com/namespaces/sfa"
The minimal size for a Pages index.xml file is : 520038 bytes.
If you retrieve the index.xml file, we may try to rebuild an usable package.
Ask the recovery tool to transfer the recovered file on an other media.
If the document embedded pictures, the index will give their path and their size which may be useful to recover them.
Yvan KOENIG (VALLAURIS, France) lundi 1 novembre 2010 10:27:44