I was using LibreOffice 3.3.1 to do some document editing when my system froze in the middle of an autosave. (It's an irregular hardware issue as far as I can tell). Unfortunately, both the document and it's backup now show a file size of 0 kb.

I am running OpenSuse 11.2, and I'm fairly sure I used ext4 as the file system when installing. What tool(s) should I consider to try to retrieve my data, assuming there is anything left to retrieve? I have found references to Testdisk, and I have an older copy of Knoppix available. Is there anything else out there that I should look into?